What is the average age of students who have city code "NYC" and have secretary votes for the spring election cycle?
SELECT avg(T1.Age) FROM STUDENT AS T1 JOIN VOTING_RECORD AS T2 ON T1.StuID  =  SECRETARY_Vote WHERE T1.city_code  =  "NYC" AND T2.Election_Cycle  =  "Spring"
"NYC" şehir kodu olan ve bahar seçim döngüsü için sekreter oyları olan öğrencilerin ortalama yaşı nedir?