For the year ended December 31, 2016, Beep Inc. recorded pre-tax book income of $600. To compute taxable income for federal income tax purposes, the following items should be noted:

Life insurance premiums paid. $70

Stock option vesting deductible for book purposes but not immediately deductible for tax purposes. $80

Statutory corporate income tax rate. 21%

By how much did deferred tax assets increase?