Hi everyone, can you please help me clear up some tyre confusion

I recently bought a 2004 A4 Tdi Avant, at its MOT it had 2 advisories for tyres at minimum tread.
Checking round the car there is a mixture of speed and load ratings, we have,
205/55/ZR16 94W
205/55/R16 91V
205/55/R16 91W
Could someone tell me the standard size, speed rating and load rating. I've checked the manual and the haynes manual and searched on the forum but cant find a deffinate answer.