CREATE TABLE table_203_168 (id DECIMAL, "team name" TEXT, "leagues" TEXT, "base" TEXT, "year started" TEXT, "year ended" TEXT, "notable riders" TEXT)

how many teams were ended in the last ten years ?
SELECT COUNT("team name") FROM table_203_168 WHERE "year ended" >= present_ref - 10
SELECT COUNT("team name") FROM "table_203_168" WHERE "year ended" >= "present_ref" - 10