Table: web_browser_usage
Columns: period
internet_explorer
firefox
safari
opera
netscape
other_mozilla

Question: What percentage of users were using Netscape during the period in which 21.67% were using Firefox?
SQL: SELECT "netscape" FROM web_browser_usage WHERE "firefox" = '21.67%'

Question: What percentage of users were using Safari during the period in which 2.33% were using Opera?
SQL: SELECT "safari" FROM web_browser_usage WHERE "opera" = '2.33%'

Question: What percentage of users were using Netscape during the period in which 63.67% were using Internet Explorer?
SQL: SELECT "netscape" FROM web_browser_usage WHERE "internet_explorer" = '63.67%'

Question: What percentage of users were using Firefox during the period in which *0.77% were using Netscape?
SQL: SELECT "firefox" FROM web_browser_usage WHERE "netscape" = '*0.77%'

Question: What percentage of users were using other Mozilla browsers during the period in which 2.29% were using Opera?
SQL: SELECT "other_mozilla" FROM web_browser_usage WHERE "opera" = '2.29%'

Question: What percentage of users were using Opera during the period in which 63.67% were using Internet Explorer?
SQL: SELECT "opera" FROM web_browser_usage WHERE "internet_explorer" = '63.67%'