text: # Write your MySQL query statement below
  select 
  round((select count(distinct a.player_id) from Activity a
  inner join 
  (select player_id, min(event_date) as first_logged 
      from Activity 
      group by player_id) b on datediff(a.event_date, b.first_logged)=1
      and a.player_id = b.player_id)
      /
      (select count(distinct player_id) from Activity),2) as fraction;
  