-2.17% is the change from 830 to 812
Calculation steps:
[( 812 - 830 ) ÷ 830] x 100 = -2.17%
Formula
Percentage change = [(812 - 830) / 830] x 100
Subtract the new number by the original number
812 - 830 = -18
-18 ÷ 830 = -0.021686746987951807
-0.021686746987951807 x 100 = -2.17%