While I am not familiar with the NY state tests, my middle kid had perfect math scores on the PA (PSSA) math tests in 4th and 8th. When she was in 4th grade, they still published detailed charts with the scores. There are typically about 70 questions on the test, and about 1 in 200 kids got a perfect score.
Kid also got perfect writing scores on the PSSA in 5th and 8th, but don't know how frequent those perfect scores are.
Don't know if the tests are similar, but when we mentioned the 4th grade results to the school, they said they expect all of their students to score like that. Of course, they don't all have perfect scores, but given the number of gifted/very bright kids in our district, there are likely some perfect section scores each year in every grade.
Unfortunately, the state tests test grade level stuff. So while a perfect scorer is likely operating above grade level, just how far above is tough to tell.
