-50.9% is the change from 391 to 192
Calculation steps:
[( 192 - 391 ) ÷ 391] x 100 = -50.9%
Formula
Percentage change = [(192 - 391) / 391] x 100
Subtract the new number by the original number
192 - 391 = -199
-199 ÷ 391 = -0.5089514066496164
-0.5089514066496164 x 100 = -50.9%