OK Dude, I'll give it a go, without looking anything up.

First off, the only bootleg out pre 86 was "From 1999 till now", and contained no new songs. You asked for bootlegs, not studio sessions, so I'm using some leeway here, to get to an answer!

Therefore, only official releases can be counted! Add PR to ATWIAD, plus the B-sides, and we get 26.

Add "4 the tears in your eyes", Thats 27 for sure.

Then, it could be argued. Shiela E admitted she only contributed vocals to her first album, therefore Shortberry Strawcake and Too sexy are prince solo efforts. As is Tricky. You could probably throw Susannahs pyjamas and Yes in there too. Add A Love Bizarre and we are looking at 33!

What have I missed!