[Stratascratch/SQL] User Feature Completion

with cte as (
	select feature_id, user_id, max(step_reached) as max_step
    from facebook_product_features_realizations
    group by feature_id, user_id)

select f.feature_id, ifnull(avg(cte.max_step/f.n_steps)*100, 0) avg_percentage
from facebook_product_features f
left join cte on f.feature_id = cte.feature_id
group by f.feature_id;