You are, most likely, not a part year resident of VT. For tax purposes, you are a full year resident.
See:
https://ttlc.intuit.com/community/state-taxes/discussion/re-do-expats-need-to-file-state-returns-if-...
https://ttlc.intuit.com/community/state-taxes/discussion/what-is-my-state-of-residence-if-i-don-t-li...
