user: Question: What percentage of users were using Internet Explorer during the period in which 2.1% were using mobile browsers?
Columns: ['Period', 'Internet Explorer', 'Firefox', 'Chrome', 'Safari', 'Opera', 'Other Mozilla', 'Mobile']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['December 2010', '42.12%', '28.82%', '11.18%', '5.70%', '3.67%', '0.52%', '6.4%']
SQL:

assistant: SELECT "Internet Explorer" FROM "Table" WHERE "Mobile" = '2.1%';