-86.09% is the change from 647 to 90
Calculation steps:
[( 90 - 647 ) ÷ 647] x 100 = -86.09%
Formula
Percentage change = [(90 - 647) / 647] x 100
Subtract the new number by the original number
90 - 647 = -557
-557 ÷ 647 = -0.8608964451313755
-0.8608964451313755 x 100 = -86.09%