Where's the "zero times" option?
I dunno what London's toilets are made of, but porcelain ones here are generally cold enough that one finds out pretty quickly if the seat isn't down. Falling in requires a special kind of person, drunk or not.
I grew up in a house with two women and I lived with two women in college, so for the vast majority of my life, any time a toilet seat was left up, I was berated for being an inconsiderate dickhole. Consequently, I learned long ago to always put the toilet seat down, which makes falling in while using the toilet very, very difficult.
The hole in the seat is a finite size, and it's uncomfortable to land in any position but 'dead center'. Oh, and wang touch toilet = cut it off, so more incentive to be accurate.
