-69.2% is the change from 815 to 251
Calculation steps:
[( 251 - 815 ) ÷ 815] x 100 = -69.2%
Formula
Percentage change = [(251 - 815) / 815] x 100
Subtract the new number by the original number
251 - 815 = -564
-564 ÷ 815 = -0.6920245398773006
-0.6920245398773006 x 100 = -69.2%