CREATE TABLE table_15253 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" FLOAT)

What is the total points of teams using a ligier js11/15 chassis?
SELECT COUNT("Points") FROM table_15253 WHERE "Chassis" = 'ligier js11/15'
SELECT COUNT("Points") FROM "table_15253" WHERE "Chassis" = 'ligier js11/15'