CREATE TABLE table_name_91 (grid INT, driver VARCHAR, points VARCHAR)

What's the highest grid of Ronnie Bremer, who had more than 18 points?
SELECT MAX(grid) FROM table_name_91 WHERE driver = "ronnie bremer" AND points > 18
SELECT MAX("grid") FROM "table_name_91" WHERE "driver" = "ronnie bremer" AND "points" > 18