-62.12% is the change from 821 to 311
Calculation steps:
[( 311 - 821 ) ÷ 821] x 100 = -62.12%
Formula
Percentage change = [(311 - 821) / 821] x 100
Subtract the new number by the original number
311 - 821 = -510
-510 ÷ 821 = -0.6211936662606578
-0.6211936662606578 x 100 = -62.12%