query: SELECT YEAR ,  avg(attendance) FROM home_game GROUP BY YEAR;
question: Each year, are returning year and the average number attendance home game.
query_toks: SELECT YEAR , avg ( attendance ) FROM home_game GROUP BY YEAR ;
query_toks_no_value: select year , avg ( attendance ) from home_game group by year
question_toks: Each year, are returning year and the average number attendance home game.