CREATE TABLE table_13301 ("Period" CLOB, "Internet Explorer" CLOB, "Firefox" CLOB, "Safari" CLOB, "Opera" CLOB, "Netscape" CLOB, "Other Mozilla" CLOB)

What percentage of users were using Netscape during the period in which 21.67% were using Firefox?
SELECT "Netscape" FROM table_13301 WHERE "Firefox" = '21.67%'
SELECT "Netscape" FROM "table_13301" WHERE "Firefox" = '21.67%'