Question: How many stations had more than 14 bikes available on average or were installed in december?
SQL: select count ( * )  from  ( SELECT T1.name FROM station AS T1 JOIN status AS T2 ON T1.id   =   T2.station_id GROUP BY T2.station_id HAVING avg ( T2.bikes_available )   >  14 UNION SELECT name FROM station WHERE installation_date LIKE "12/%" )