Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What percentage of users were using Internet Explorer during the period in which 2.1% were using mobile browsers?

### Inputs:
table_name: table, columns: ['Period', 'Internet Explorer', 'Firefox', 'Chrome', 'Safari', 'Opera', 'Other Mozilla', 'Mobile']

### Response:
SELECT Internet Explorer FROM table WHERE Mobile = 2.1%