The local newspapers posted links to the data - I still have no idea of how my individual child did.
This *should* work for your district:
http://data.nysed.gov/assessment.php?year=2015&instid=800000053180
You should also be able to look up by school. You can view by percentages or by numbers. You have to use the "filter" option to get specific grades.
Opt outs varied greatly by district, and even within the district. Statewide, the average % of students opting out was about 20%. At my daughter's school, it was MUCH less than that.
There's some interesting data about those who opted out, FWIW. Apparently, the state data analysis has come up this idea that those who opt out are more likely to be white and less likely to be economically disadvantaged - and more likely to have scored in the Level 1 range if they did take the exam!