I hold true that the network must be above 95% for 95% to be reached.
The simplest argument is that every miner must convert to the 'new fork' before they can find a 'new fork' block.
That time that they convert will be, on average, half way between their 'previous fork' block and their 'new fork' block.
When miners are producing 'new fork' blocks they obviously must have convert before that.
950 of the last 1000 blocks (what they actually test for) is not necessarily produced by 95% of the hashrate, and certainly not 95% of the network (most nodes don't mine). Again, I refer to
Organofcorti's blog for the explanation and details.
That's discussing 75% where the XT morons tried to make it lower and screwed up coz they didn't work out the side effect on probabilities when dropping it so low ...
Edit: see point 4.