-50.15% is the change from 686 to 342
Calculation steps:
[( 342 - 686 ) ÷ 686] x 100 = -50.15%
Formula
Percentage change = [(342 - 686) / 686] x 100
Subtract the new number by the original number
342 - 686 = -344
-344 ÷ 686 = -0.5014577259475219
-0.5014577259475219 x 100 = -50.15%