CREATE TABLE table_204_373 (id DECIMAL, "wager" TEXT, "winner" TEXT, "loser" TEXT, "location" TEXT, "date" TEXT)

number of mocho cota matches held in mexico city in 1983 or 1984
SELECT COUNT(*) FROM table_204_373 WHERE "location" = 'mexico city' AND "date" IN (1983, 1984)
SELECT COUNT(*) FROM "table_204_373" WHERE "date" IN (1983, 1984) AND "location" = 'mexico city'