-50.58% is the change from 686 to 339
Calculation steps:
[( 339 - 686 ) ÷ 686] x 100 = -50.58%
Formula
Percentage change = [(339 - 686) / 686] x 100
Subtract the new number by the original number
339 - 686 = -347
-347 ÷ 686 = -0.5058309037900874
-0.5058309037900874 x 100 = -50.58%