CREATE TABLE table_68749 ("Date" TEXT, "Opponent" TEXT, "Score" TEXT, "Loss" TEXT, "Attendance" FLOAT, "Record" TEXT)

What is the total attendance at games against the New York Mets with a record of 18-18?
SELECT COUNT("Attendance") FROM table_68749 WHERE "Opponent" = 'new york mets' AND "Record" = '18-18'
SELECT COUNT("Attendance") FROM "table_68749" WHERE "Opponent" = 'new york mets' AND "Record" = '18-18'