CREATE TABLE table_52430 ("Team" CLOB, "Stadium" CLOB, "Capacity" FLOAT, "Highest" FLOAT, "Lowest" FLOAT, "Average" FLOAT)

What is the lowest attendance for a stadium that has an average smaller than 307?
SELECT AVG("Lowest") FROM table_52430 WHERE "Average" < '307'
SELECT AVG("Lowest") FROM "table_52430" WHERE "Average" < '307'