-80.7% is the change from 513 to 99
Calculation steps:
[( 99 - 513 ) ÷ 513] x 100 = -80.7%
Formula
Percentage change = [(99 - 513) / 513] x 100
Subtract the new number by the original number
99 - 513 = -414
-414 ÷ 513 = -0.8070175438596491
-0.8070175438596491 x 100 = -80.7%