CREATE TABLE table_name_59 (net_yds INT, long VARCHAR, start VARCHAR)

What is the average net yds for the player who had a long of 68 and started after 1984?
SELECT AVG(net_yds) FROM table_name_59 WHERE long = 68 AND start > 1984
SELECT AVG("net_yds") FROM "table_name_59" WHERE "long" = 68 AND "start" > 1984