CREATE TABLE table_74648 ("Rank" TEXT, "County" TEXT, "Population  ( 1960 ) " FLOAT, "Population  ( 2000 ) " FLOAT, "Population  ( 2040 ) " FLOAT)

What was the population of a county in 1960 that had a population of 467,052 in 2000 and 78,812 in 2040?
SELECT AVG("Population (1960)") FROM table_74648 WHERE "Population (2000)" > '467,052' AND "Population (2040)" = '78,812'
SELECT AVG("Population (1960)") FROM "table_74648" WHERE "Population (2000)" > '467,052' AND "Population (2040)" = '78,812'