Year Expenditures
Tax Revenues
GDP
1
$410
$345
$6,900
2
$460
$365
$7,700
3
4
$520
$480
$395
$7,900
$420
$8,700
Suppose that initially there is no public debt. Using the above table, the public debt over this four year period would have increase by $__.
(Enter your response as a whole number.)