-50.44% is the change from 686 to 340
Calculation steps:
[( 340 - 686 ) ÷ 686] x 100 = -50.44%
Formula
Percentage change = [(340 - 686) / 686] x 100
Subtract the new number by the original number
340 - 686 = -346
-346 ÷ 686 = -0.5043731778425656
-0.5043731778425656 x 100 = -50.44%