### Database Schema:
CREATE TABLE podcasts (
	podcast_id	TEXT	NULL	PRIMARY KEY,
	itunes_id	INTEGER	NOT NULL,
	slug	TEXT	NOT NULL,
	itunes_url	TEXT	NOT NULL,
	title	TEXT	NOT NULL
);

CREATE TABLE reviews (
	podcast_id	TEXT	NOT NULL,
	title	TEXT	NOT NULL,
	content	TEXT	NOT NULL,
	rating	INTEGER	NOT NULL,
	author_id	TEXT	NOT NULL,
	created_at	TEXT	NOT NULL,
	foreign key (podcast_id) references podcasts (podcast_id)
);

CREATE TABLE runs (
	run_at	TEXT	NOT NULL,
	max_rowid	INTEGER	NOT NULL,
	reviews_added	INTEGER	NOT NULL
);

CREATE TABLE categories (
	podcast_id	TEXT	NOT NULL	PRIMARY KEY,
	category	TEXT	NOT NULL	PRIMARY KEY,
	foreign key (podcast_id) references podcasts (podcast_id)
);

### User's Query:
What is the percentage of reviews added each year of the total reviews added?

### Extra Knowledge:
review added each year refers to runs_at like '2021%' and runs_at like '2022%'; percentage for 2021 = Divide (Sum(reviews_added(runs_at like '2021%)), Sum(reviews_added)) * 100; percentage of 2022 = Divide (Sum(reviews_added(runs_at like '2022%')), Sum(reviews_added)) * 100
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