CREATE TABLE table_55843 ("Year" FLOAT, "MRHMA" TEXT, "USCA" TEXT, "RTHK" TEXT, "Joint Music Award" TEXT, "Total" FLOAT)

How many Joint Music Awards are there when the Total is larger than 18, in a Year after 2007?
SELECT "Joint Music Award" FROM table_55843 WHERE "Total" > '18' AND "Year" > '2007'
SELECT "Joint Music Award" FROM "table_55843" WHERE "Total" > '18' AND "Year" > '2007'