-76.28% is the change from 215 to 51
Calculation steps:
[( 51 - 215 ) ÷ 215] x 100 = -76.28%
Formula
Percentage change = [(51 - 215) / 215] x 100
Subtract the new number by the original number
51 - 215 = -164
-164 ÷ 215 = -0.7627906976744186
-0.7627906976744186 x 100 = -76.28%