-19.53% is the change from 645 to 519
Calculation steps:
[( 519 - 645 ) ÷ 645] x 100 = -19.53%
Formula
Percentage change = [(519 - 645) / 645] x 100
Subtract the new number by the original number
519 - 645 = -126
-126 ÷ 645 = -0.19534883720930232
-0.19534883720930232 x 100 = -19.53%