This was mostly down to the fall in the value of the pound, which hit a thirty-year low right after the UK voted to leave the EU in the June 23 referendum.
The combined wealth of all the UK's current billionaires is $295 billion (£226 billion), down from $395 billion ($303 billion).
Overall there are 2,473 dollar billionaires in the world, with a combined wealth of $7.68 trillion (£5.89 trillion).
Asia has the fastest growth rate of billionaires, with 678 new ones since the survey was done last year - four times more than the US.
The report has also done a profile of the typical billionaire:
- Education: 70% have done a bachelor's degree, but only 22% went on to do a masters.
- 57% were self-made, up 7% from last year.
- Finance is still the biggest billionaire industry, with 15.2% of billionaires from that sector.
- Industrial conglomerates came second most common sector at 12.8% with real estate third at 5.7%.
- Love and Marriage: 85% of today's billionaires are married, down 1% from last year.
- Charity: Most billionaires are pretty generous, donating an average of $110 million each over a lifetime. Education is the cause closest to their heart, making up 54.5% of donations.
- Over $4 trillion will be passed on by billionaires through inheritance in the next 20 years.