CREATE TABLE table_204_590 (id DECIMAL, "year" DECIMAL, "division" DECIMAL, "league" TEXT, "regular season" TEXT, "playoffs" TEXT, "open cup" TEXT, "avg. attendance" DECIMAL)

how many years did this team not qualify for the open cup ?
SELECT COUNT("year") FROM table_204_590 WHERE "open cup" = 'did not qualify'
SELECT COUNT("year") FROM "table_204_590" WHERE "open cup" = 'did not qualify'