Somerset Maugham once famously described Monaco as "a sunny place for shady people".

But the truth is that Monaco, along with most of the old, traditional tax havens, is no longer quite as shady.

If you really want to hide money, no questions asked, the likelihood these days is you'll end up somewhere like Panama.

The explanation tells you much about the state of the global tax havens business, a business which is under greater threat than ever before.

To understand why, have a look at the enormous cache of documents leaked from Panamanian firm Mossack Fonseca .

Forget, for the time being, the exciting revelations about Vladimir Putin and his friends and look at the overall numbers.

Mossack Fonseca has been dramatically shutting down companies over the past five or six years.

Remember that if you want to hide money away you will usually have to set up a shell company in which to put it.

At its peak in 2005, Mossack Fonseca was setting up 12,287 companies a year and deactivating 6,339. Last year it set up just 4,341 and deactivated 8,864.

Since 2009 the number of companies being deactivated has dramatically outpaced the number being created.

This is only one piece of evidence for a much broader phenomenon: the sharp, dramatic decline in the use of tax havens for shady purposes.

While we're at it, there's a real danger here of tarring everyone with the wrong brush.

There are plenty of legitimate uses for offshore jurisdictions, both for individuals and for businesses.

You might be a company with intellectual property which is really international and should not be rooted in any specific country, you could be a worker who gets their salary in one country and mostly lives in another, you could be worried about the financial stability, or the threat of a government coup, in the country you're working, and so want to keep the money elsewhere.

Though the offshore world is used by people avoiding and evading tax, and sometimes hiding money gotten through ill-gotten gains, that is not its purpose.

But the key point is that either way, there have been a whole range of measures introduced over the past five years or so which have, gradually, clamped down on tax havens, which help explain the decline in those charts.

There are measures being pushed through the G20, there are rules being imposed by the OECD and, most of all (since in international treaties nothing much matters unless the US is involved), there is the FATCA (Foreign Account Tax Compliance Act) regime imposed by Washington.

Through a whole variety of levers - largely clamping down on secrecy over ownership and over sources of money - the ability of tax havens to shelter money altogether from tax authorities has been dramatically diminished.

Most offshore regimes have been pretty diligent in imposing these new rules, including Switzerland, the Channel Islands and even, to a lesser extent, British overseas territories such as the British Virgin Islands.

The upshot is that it has become far, far more difficult to hide away money. Witness the FIFA scandal, witness the Petrobras scandal in Brazil, witness the Malaysian development fund scandal.

The common factor is that money which might hitherto have remained hidden in Swiss bank accounts has now been upturned and exposed.

Anyone wanting hide money away offshore will still, at some point, want to get their hands on that money, and that normally means channelling it back through UK or US banks, and here, too, banks have been forced to impose yet more checks on who owns the money and the companies.

However, when you talk to people in the offshore industry, they will tell you that there are still one or two countries which are resistant, which are doing everything they can not to impose these regulations.

At the top of that list is Panama - though the interesting thing to note from the Panama leaks is that even there, activity is starting to dry up.