If they were granted while working in New York, then the amount of vested stock income you would include in your income would allocated based on how may days within the vesting period you worked in New York.
For example, if the stock was granted and then you left NY 90 days later, you'd prorate your vested stock income to New York based on 90 days/# of days in vesting period. If the vesting period was one year, then you'd report roughly 25% (90/365) of the vested stock income on your New York nonresident return. Your employer may also provide a statement.
Since you didn't live in New York during the full vesting period, you wouldn't need to include all of your vesting income on your New York return.
@th1nkannie
[Edited 3/5 at 4:40pm Eastern]
