-87.89% is the change from 421 to 51
Calculation steps:
[( 51 - 421 ) ÷ 421] x 100 = -87.89%
Formula
Percentage change = [(51 - 421) / 421] x 100
Subtract the new number by the original number
51 - 421 = -370
-370 ÷ 421 = -0.8788598574821853
-0.8788598574821853 x 100 = -87.89%