-68.62% is the change from 819 to 257
Calculation steps:
[( 257 - 819 ) ÷ 819] x 100 = -68.62%
Formula
Percentage change = [(257 - 819) / 819] x 100
Subtract the new number by the original number
257 - 819 = -562
-562 ÷ 819 = -0.6862026862026862
-0.6862026862026862 x 100 = -68.62%