query: SELECT max(years_working) ,  min(years_working) ,  avg(years_working) FROM school_bus
question: What-what on a school bus is a , and average years maximum minimum have spent a-working?
query_toks: SELECT max ( years_working ) , min ( years_working ) , avg ( years_working ) FROM school_bus
query_toks_no_value: select max ( years_working ) , min ( years_working ) , avg ( years_working ) from school_bus
question_toks: What-what on a school bus is a , and average years maximum minimum have spent a-working?