-63.13% is the change from 830 to 306
Calculation steps:
[( 306 - 830 ) ÷ 830] x 100 = -63.13%
Formula
Percentage change = [(306 - 830) / 830] x 100
Subtract the new number by the original number
306 - 830 = -524
-524 ÷ 830 = -0.6313253012048192
-0.6313253012048192 x 100 = -63.13%