-48.34% is the change from 815 to 421
Calculation steps:
[( 421 - 815 ) ÷ 815] x 100 = -48.34%
Formula
Percentage change = [(421 - 815) / 815] x 100
Subtract the new number by the original number
421 - 815 = -394
-394 ÷ 815 = -0.4834355828220859
-0.4834355828220859 x 100 = -48.34%