UK - number one in tornados

There was yet another Tornado to hit the Midlands yesterday, and after reading about it on the net i came across this

"With the amount of media coverage dedicated to American storm-chasers, you'd think the US had the monopoly on these twisters. It doesn't. It might come as a shock, but the United Kingdom is actually the world's most tornado-prone nation. This fact was calculated by the late Dr Fujita of Chicago University. He devised the standard method of measuring tornado intensity. Fujita figured that since Britain has an average of 33 tornadoes every year in an area 38 times smaller than the USA, you're twice as likely to witness a tornado here. "

I remember when one hit Ferriby back in about 1999, and it was when i was doing my paper round - it actually threw me off the bike, and i couldn't hardly ride my bike.
There was also one back in about 1989 that hit Hull i remember because my Dad was affected by it - upon leaving work a piece of chimney hit him on the head.