-63.04% is the change from 138 to 51
Calculation steps:
[( 51 - 138 ) ÷ 138] x 100 = -63.04%
Formula
Percentage change = [(51 - 138) / 138] x 100
Subtract the new number by the original number
51 - 138 = -87
-87 ÷ 138 = -0.6304347826086957
-0.6304347826086957 x 100 = -63.04%