-91.63% is the change from 609 to 51
Calculation steps:
[( 51 - 609 ) ÷ 609] x 100 = -91.63%
Formula
Percentage change = [(51 - 609) / 609] x 100
Subtract the new number by the original number
51 - 609 = -558
-558 ÷ 609 = -0.916256157635468
-0.916256157635468 x 100 = -91.63%