-- Database schema
| runs : run_at [ TEXT ] , max_rowid [ INTEGER ] , reviews_added [ INTEGER ] | podcasts : podcast_id [ TEXT ] primary_key , itunes_id [ INTEGER ] , slug [ TEXT ] , itunes_url [ TEXT ] , title [ TEXT ] | reviews : podcast_id [ TEXT ] , title [ TEXT ] , content [ TEXT ] , rating [ INTEGER ] , author_id [ TEXT ] , created_at [ TEXT ] | categories : podcast_id [ TEXT ] , category [ TEXT ] |
-- -- What is the percentage of reviews added each year of the total reviews added?

SELECT CAST((SUM(CASE WHEN run_at LIKE '2022-%' THEN reviews_added ELSE 0 END) - SUM(CASE WHEN run_at LIKE '2021-%' THEN reviews_added ELSE 0 END)) AS REAL) * 100 / SUM(reviews_added) OR '%' "percentage" FROM runs;