-91.2% is the change from 830 to 73
Calculation steps:
[( 73 - 830 ) ÷ 830] x 100 = -91.2%
Formula
Percentage change = [(73 - 830) / 830] x 100
Subtract the new number by the original number
73 - 830 = -757
-757 ÷ 830 = -0.9120481927710843
-0.9120481927710843 x 100 = -91.2%