CREATE TABLE table_51367 ("Year" FLOAT, "Property Taxes" CLOB, "Investment Earnings" CLOB, "Other Local Sources" CLOB, "State & Federal" CLOB, "Total Revenue" CLOB)

What were the investment earnings in a year when total revenue was $21,779,618?
SELECT "Investment Earnings" FROM table_51367 WHERE "Total Revenue" = '21,779,618'
SELECT "Investment Earnings" FROM "table_51367" WHERE "Total Revenue" = '21,779,618'