-69.88% is the change from 830 to 250
Calculation steps:
[( 250 - 830 ) ÷ 830] x 100 = -69.88%
Formula
Percentage change = [(250 - 830) / 830] x 100
Subtract the new number by the original number
250 - 830 = -580
-580 ÷ 830 = -0.6987951807228916
-0.6987951807228916 x 100 = -69.88%