Trouble is it's a crappy quality cropped photo of an already crappy original in the ebay listing so there's not much to go on. They all had straight forks with the exception of the very early 1988 (I think). The 91 and 92 were both purple/blue (I have a bit of colour blindness telling the difference) with black forks and they both had the same front tyres. There's not really much else to be seen. Definitely either 91 or 92. I'd say 92.