CREATE TABLE table_name_28 (grid NUMBER, driver VARCHAR2, laps VARCHAR2)

What is the number of the grid for Johnny Herbert with more than 52 laps?
SELECT SUM(grid) FROM table_name_28 WHERE driver = "johnny herbert" AND laps > 52
SELECT SUM("grid") FROM "table_name_28" WHERE "driver" = "johnny herbert" AND "laps" > 52