-80.16% is the change from 257 to 51
Calculation steps:
[( 51 - 257 ) ÷ 257] x 100 = -80.16%
Formula
Percentage change = [(51 - 257) / 257] x 100
Subtract the new number by the original number
51 - 257 = -206
-206 ÷ 257 = -0.8015564202334631
-0.8015564202334631 x 100 = -80.16%