-87.25% is the change from 400 to 51
Calculation steps:
[( 51 - 400 ) ÷ 400] x 100 = -87.25%
Formula
Percentage change = [(51 - 400) / 400] x 100
Subtract the new number by the original number
51 - 400 = -349
-349 ÷ 400 = -0.8725
-0.8725 x 100 = -87.25%