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The first two years of the Trump White House have been eventful, to say the least. But let's ignore the drama and instead focus on the numbers.

We're tracking the president's progress on his agenda and how it is received by the American public and the wider world.

And there are interesting - and surprising - comparisons with some of his predecessors.

How are his approval ratings?

Donald Trump began his term as one of the most unpopular presidents in the modern era and he remains so.

His approval rating is just 37%, according to Gallup. Presidents Barack Obama (50%), George W Bush (58%) and Bill Clinton (54%) were all higher at this point.

The only president in recent decades to have anything like Mr Trump's low rating at this stage was, perhaps surprisingly, Ronald Reagan, who was also languishing at 37% in 1983. His numbers slowly improved after that and he went on to win a second term as president.

One upside for Mr Trump is that he still has the backing of Republican voters - 88% of them approve of his presidency. If that number stays high, it's unlikely he'll face a serious challenge to be the Republican candidate in 2020.

How has he run the White House?

President Trump's administration has repeatedly been branded as chaotic and dysfunctional by his critics.

There is a long list of senior officials who have either quit, been fired or forced out of the White House - but has the turnover been worse than previous administrations?

Well, yes, it has. Research by the Brookings Institution found that 65% of his senior-ranking advisers had left their job within the two-year mark. That's considerably more than most of his recent predecessors.

Usually, a president's top team sticks together for the first year and then changes a little in the second - but for Mr Trump, the departures have been fairly regular since day one.

Has he kept his campaign promises?

The lack of stability in the White House has shown when it comes to measuring Mr Trump's success with policy.

He has had trouble delivering in areas where he's needed to navigate the corridors of Congress, despite controlling both chambers until Democrats regained the House at the start of January.

On healthcare, for example, he failed on his promise to kill off President Obama's Affordable Care Act, which helped more than 20 million previously uninsured Americans get health cover but suffered from rising premiums.

His main legislative success was passing a major tax reform bill, which saw corporation tax was reduced from 35% to 21%. However, individual cuts for families failed to help Republicans in the mid-term elections.

His other big success was getting two new Supreme Court judges confirmed, including Brett Kavanaugh, who faced allegations of sexual assault during his confirmation process.

Elsewhere, the president has used executive orders to meet symbolic policy goals like moving of the US embassy in Israel to Jerusalem and the withdrawal of the US from the Paris climate agreement. He has also moved to draw down troop levels overseas, including in Afghanistan and Syria.

But overall, independent fact-checking website Politifact says that President Trump has delivered on relatively few of his campaign promises, while almost half have been blocked or dropped.

Has he delivered on immigration reforms?

Building a border wall paid for by Mexico was President Trump's signature issue during the election campaign but it still appears unlikely to happen.

Congress has approved $1.7bn in funding for 124 miles of new and replacement barrier since Mr Trump entered the White House, but estimates for building the president's desired wall range from from $12bn to $70bn.

In December, after criticism over the lack of progress on the wall from some conservative commentators, President Trump triggered an unprecedented 35-day partial shutdown of the US government.

He had hoped to pressure Democrats into making a deal, but he was eventually forced into reopening the government without an agreement.

The US economy lost $11bn during the five-week period but about $8bn would be recouped as employees receive back pay, according to the non-partisan Congressional Budget Office.

Throughout the shutdown, Mr Trump argued that the wall was needed to stem a "growing humanitarian and security crisis at our southern border", involving "thousands of illegal immigrants".

However, figures show that illegal border crossings have seen an overall decline since 2000.

President Trump continues to press Congress to change US immigration laws, including ending the visa lottery system and "chain migration" that gives priority to relatives of existing legal US residents.

The Supreme Court also handed him a victory in June last year, when it upheld his ban on people from several Muslim-majority countries entering the US on grounds of national security.

How has the economy fared under Trump?

During the campaign, Mr Trump vowed to create 25 million jobs over 10 years and become "the greatest jobs president... ever".

He used to claim the actual unemployment rate was more than 40%. Now he's America's CEO, he's embracing the same jobless figures he once dismissed as "phony".

Those figures do show, though, that job creation under Mr Trump during his first two years in office fell slightly when compared to President Obama's final two.

However, the basic trajectory of the economy under President Trump remains the same as it was under President Obama - the unemployment rate is historically low and wages are growing at a faster rate in recent months.

But there are some concerns for Mr Trump. Global economic growth is down and his decision to start a trade war with China led to retaliatory tariffs on US goods worth hundreds of billions of dollars.

The president has been quick to take credit for booming stock markets over the past couple of years, but they have started to wobble in recent weeks.

How are things looking for 2020?

The next presidential election may be more than 18 months away, but the campaign has already kicked off.

Encouraged by a good set of mid-term election results, the Democrats are optimistic on retaking the White House.

Several candidates have already announced that they are standing for the Democratic nomination, with the two biggest hitters being senators - Elizabeth Warren and Kamala Harris. Other potentials, like former Vice President Joe Biden, are still mulling a run.

But whoever the candidate turns out to be, the early signs are that President Trump is in for another tough battle.

A recent poll found that seven possible Democrat rivals are all outperforming the president in hypothetical head-to-heads. While that should be taken with a pinch of salt this far out from election day, it will make Republicans feel a little nervous.