-98.63% is the change from 511 to 7
Calculation steps:
[( 7 - 511 ) ÷ 511] x 100 = -98.63%
Formula
Percentage change = [(7 - 511) / 511] x 100
Subtract the new number by the original number
7 - 511 = -504
-504 ÷ 511 = -0.9863013698630136
-0.9863013698630136 x 100 = -98.63%