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

what was the last year where this team was a part of the usl a league ?
SELECT MAX("year") FROM table_204_590 WHERE "league" = 'usl a-league'
SELECT MAX("year") FROM "table_204_590" WHERE "league" = 'usl a-league'