CREATE TABLE table_66075 ("Period" TEXT, "Internet Explorer" TEXT, "Firefox" TEXT, "Chrome" TEXT, "Safari" TEXT, "Opera" TEXT, "Other Mozilla" TEXT, "Mobile" TEXT)

What percentage of users were using Internet Explorer during the period in which 2.1% were using mobile browsers?
SELECT "Internet Explorer" FROM table_66075 WHERE "Mobile" = '2.1%'
SELECT "Internet Explorer" FROM "table_66075" WHERE "Mobile" = '2.1%'