-74.46% is the change from 830 to 212
Calculation steps:
[( 212 - 830 ) ÷ 830] x 100 = -74.46%
Formula
Percentage change = [(212 - 830) / 830] x 100
Subtract the new number by the original number
212 - 830 = -618
-618 ÷ 830 = -0.744578313253012
-0.744578313253012 x 100 = -74.46%