a comic book was sold for 10 dollars in seven years later it was sold for 200 dollars .what precent is the new value

To find the percent increase, we have  ( new value -   old value ) / (old value) x 100%

(200 -10) / 10 = 190/10 = 19 x 100% = 1900%

The new value is 2000% of the old