-89.75% is the change from 644 to 66
Calculation steps:
[( 66 - 644 ) ÷ 644] x 100 = -89.75%
Formula
Percentage change = [(66 - 644) / 644] x 100
Subtract the new number by the original number
66 - 644 = -578
-578 ÷ 644 = -0.8975155279503105
-0.8975155279503105 x 100 = -89.75%