CREATE TABLE table_50418 ("City" CLOB, "State" CLOB, "2010 population" CLOB, "Peak population  ( year ) " CLOB, "Numeric decline from peak population" CLOB, "Percent decline from peak population" CLOB)

what is the percent decline from peak population when the peak population (year) is 178320 (1960)?
SELECT "Percent decline from peak population" FROM table_50418 WHERE "Peak population (year)" = '178320 (1960)'
SELECT "Percent decline from peak population" FROM "table_50418" WHERE "Peak population (year)" = '178320 (1960)'