Trial to Paid Conversion Rate

Return the percentage of users who converted from a trial to a paid plan (paid_start is not NULL), rounded to two decimals.

Table schema

Users(id INT PRIMARY KEY, trial_start DATE, paid_start DATE NULL)

Sample data

id | trial_start | paid_start
1 | 2026-01-01 | 2026-01-15
2 | 2026-01-05 | NULL
3 | 2026-02-01 | 2026-02-10
4 | 2026-02-03 | NULL