CREATE TABLE table_68074 ("Year" FLOAT, "Entrant" CLOB, "Chassis" CLOB, "Engine" CLOB, "Points" FLOAT)

Name the average points for chassis of stevens and year less than 1950
SELECT AVG("Points") FROM table_68074 WHERE "Chassis" = 'stevens' AND "Year" < '1950'
SELECT AVG("Points") FROM "table_68074" WHERE "Chassis" = 'stevens' AND "Year" < '1950'