Image copyright Getty Images Image caption She has secured one milestone, now Hillary Clinton is reaching for the stars

Hillary Clinton hailed her nomination as the presumptive Democratic candidate in the US presidential race as "a milestone". But many other countries in Asia, South America, and Europe have had women presidents, prime ministers, defence ministers, chief justices, and top bankers for a long time.

So how great is America's female leadership gap?

Women constitute 50.8% of the US population, have almost 60% of undergraduate and Master's degrees, and hold 52% of all professional-level jobs. And yet American women lag substantially behind men in reaching top leadership positions. Here are some examples.

Nasa space agency

Image copyright NASA Image caption Perhaps a woman astronaut will be the first human on Mars?

No woman has ever been head of Nasa, although astronaut Peggy A Whitson was the first woman to command the International Space Station (ISS) in 2007, and the current deputy administrator is Dava Newman, who was appointed by President Obama in 2015.

US military

Image copyright AP Image caption No woman has ever been top dog in the Pentagon

Although there has been a push for equality in the US military - the services now have several female four-star generals, for example - no woman has ever been US secretary of defence. The woman who came closest was Michele Flournoy, who was under secretary of defence from 2009 to 2012, a much more junior role.

Central Intelligence Agency (CIA)

Image copyright CIA Image caption At the CIA, men still have the top jobs and women are the side-kicks

It is no secret that women make great spies, but there has never been a female director of the CIA. In 2013, the CIA appointed its first female deputy director, Avril Haines.

Federal Bureau of Investigation (FBI)

Image copyright Reuters Image caption Serving tea at the FBI

The same story applies at the FBI: there's never been a woman director in the whole of its 108-year history. There is a female deputy chief of staff, and women hold posts as associate and assistant deputy directors. But these tend to be in supporting services such as records management and victim support.

The banking sector

Image copyright Getty Images Image caption A mostly male stock exchange floor - watching banks collapse in September 2008

Of the top four banks

The CEO of JPMorgan, is male, as are nine of its 11 board members.

The CEO of Bank of America is male, as are nine of its 13 board members.

The CEO of Citigroup is male, as are 11 of its 16 board members.

The CEO of Goldman Sachs is male, as are 11 of its 13 board members.

The first female CEO of a top US bank is Beth Mooney, who was appointed by KeyCorp in 2011. She has 11 men among the 13 board members. KeyCorp is the 22nd largest bank in the US.

US Supreme Court

Image copyright Getty Images Image caption A third of the justices on the US Supreme Court are currently women

There has never been a female chief justice of the United States - the head of the Supreme Court.

Some more facts:

Women get 47% percent of all law degrees in the US

Of the 112 justices, 108 have been men - that's a whopping 96.4%

All Supreme Court justices were males until 1981

Only four women have ever served on the US Supreme Court

But in some areas, the leadership gap is closing.

The Fed

Image copyright Reuters Image caption The light at the end of the gender inequality tunnel?

In January 2014, Janet Yellen was appointed chairperson of the US Federal Reserve - the first woman to take over the top spot in the 100-year history of the US central bank, or any major central bank.

Industry

Image copyright Getty Images Image caption Still a long way to go, but GM's CEO Mary Barra has extended her power by becoming chairman as well

Women CEOs lead just 4% of the Standard & Poor's 500 companies. But the ones that make it to the top feature high on the Forbes list of most powerful women in business.

US Department of State

Image copyright Getty Images Image caption Mrs Clinton followed in the formidable footsteps of Madeleine Albright, who became the highest-ranking woman in the history of US government in 1997. What next?

Of the last six secretaries of state, three have been female. Having followed Madeleine Albright and Condoleezza Rice into the state department, is Hillary Clinton now going where no other woman has gone before?