-50.66% is the change from 687 to 339
Calculation steps:
[( 339 - 687 ) ÷ 687] x 100 = -50.66%
Formula
Percentage change = [(339 - 687) / 687] x 100
Subtract the new number by the original number
339 - 687 = -348
-348 ÷ 687 = -0.5065502183406113
-0.5065502183406113 x 100 = -50.66%