-- Database schema
| Attributes : attribute_id [ INTEGER ] primary_key , attribute_name [ TEXT ] | Categories : category_id [ INTEGER ] primary_key , category_name [ TEXT ] | Compliments : compliment_id [ INTEGER ] primary_key , compliment_type [ TEXT ] | Days : day_id [ INTEGER ] primary_key , day_of_week [ TEXT ] | Years : year_id [ INTEGER ] primary_key , actual_year [ INTEGER ] | Business_Attributes : attribute_id [ INTEGER ] , business_id [ INTEGER ] , attribute_value [ TEXT ] | Business_Categories : business_id [ INTEGER ] , category_id [ INTEGER ] | Business_Hours : business_id [ INTEGER ] , day_id [ INTEGER ] , opening_time [ TEXT ] , closing_time [ TEXT ] | Checkins : business_id [ INTEGER ] , day_id [ INTEGER ] , label_time_0 [ TEXT ] , label_time_1 [ TEXT ] , label_time_2 [ TEXT ] , label_time_3 [ TEXT ] , label_time_4 [ TEXT ] , label_time_5 [ TEXT ] , label_time_6 [ TEXT ] , label_time_7 [ TEXT ] , label_time_8 [ TEXT ] , label_time_9 [ TEXT ] , label_time_10 [ TEXT ] , label_time_11 [ TEXT ] , label_time_12 [ TEXT ] , label_time_13 [ TEXT ] , label_time_14 [ TEXT ] , label_time_15 [ TEXT ] , label_time_16 [ TEXT ] , label_time_17 [ TEXT ] , label_time_18 [ TEXT ] , label_time_19 [ TEXT ] , label_time_20 [ TEXT ] , label_time_21 [ TEXT ] , label_time_22 [ TEXT ] , label_time_23 [ TEXT ] | Elite : user_id [ INTEGER ] , year_id [ INTEGER ] | Reviews : business_id [ INTEGER ] , user_id [ INTEGER ] , review_stars [ INTEGER ] , review_votes_funny [ TEXT ] , review_votes_useful [ TEXT ] , review_votes_cool [ TEXT ] , review_length [ TEXT ] | Tips : business_id [ INTEGER ] , user_id [ INTEGER ] , likes [ INTEGER ] , tip_length [ TEXT ] | Users_Compliments : compliment_id [ INTEGER ] , user_id [ INTEGER ] , number_of_compliments [ TEXT ] | Business : business_id [ INTEGER ] primary_key , active [ TEXT ] , city [ TEXT ] , state [ TEXT ] , stars [ REAL ] , review_count [ TEXT ] | Users : user_id [ INTEGER ] primary_key , user_yelping_since_year [ INTEGER ] , user_average_stars [ TEXT ] , user_votes_funny [ TEXT ] , user_votes_useful [ TEXT ] , user_votes_cool [ TEXT ] , user_review_count [ TEXT ] , user_fans [ TEXT ] |
-- -- What is the ratio of having the best to worse elite user in 2013?

SELECT CAST(SUM(CASE WHEN T1.user_average_stars = 1 THEN 1 ELSE 0 END) AS REAL) / COUNT(T2.user_id) , SUM(CASE WHEN T1.user_average_stars = 5 THEN 1 ELSE 0 END) * 1.0 / COUNT(T2.user_id) FROM Users AS T1 INNER JOIN Elite AS T2 ON T1.user_id = T2.user_id WHERE T2.year_id = 2013;