I didn't notice the bit that they don't offer for every performance, BUT it was definitely 200 at one point. It was a gift from Agnes Varis, something like 2-3 million dollars. It used to be touted as "200 $25 tickets in the orchestra to every performance". Maybe that's changed since it was first started, but it was most definitely 200.
I wish they would've just put on the page that rush wouldn't be offered tonight, rather than making people sit there, ready to go, and then just winding up disappointed.