CREATE TABLE table_name_63 (laps NUMBER, time_retired VARCHAR2, grid VARCHAR2)

What is the average lap total for grids under 19 and a Time/Retired of +4 laps?
SELECT AVG(laps) FROM table_name_63 WHERE time_retired = "+4 laps" AND grid < 19
SELECT AVG("laps") FROM "table_name_63" WHERE "+4 laps" = "time_retired" AND "grid" < 19