SELECT avg(num_of_staff) ,  avg(score) FROM shop
What are the average score and average staff number of all shops?
[Schema (values) (types)]: | coffee_shop |  shop : shop_id (text) , address (number) , num_of_staff (text) , score (text) , open_year (number) | member : member_id (text) , name (number) , membership_card (text) , age (text) , time_of_purchase (number) , level_of_membership (text) , address (number) | happy_hour : hh_id (text) , shop_id (number) , month (text) , num_of_shaff_in_charge (text) | happy_hour_member : hh_id (text) , member_id (number) , total_amount (text);