-99.8% is the change from 510 to 1
Calculation steps:
[( 1 - 510 ) ÷ 510] x 100 = -99.8%
Formula
Percentage change = [(1 - 510) / 510] x 100
Subtract the new number by the original number
1 - 510 = -509
-509 ÷ 510 = -0.9980392156862745
-0.9980392156862745 x 100 = -99.8%