-92.57% is the change from 686 to 51
Calculation steps:
[( 51 - 686 ) ÷ 686] x 100 = -92.57%
Formula
Percentage change = [(51 - 686) / 686] x 100
Subtract the new number by the original number
51 - 686 = -635
-635 ÷ 686 = -0.9256559766763849
-0.9256559766763849 x 100 = -92.57%