-59.15% is the change from 639 to 261
Calculation steps:
[( 261 - 639 ) ÷ 639] x 100 = -59.15%
Formula
Percentage change = [(261 - 639) / 639] x 100
Subtract the new number by the original number
261 - 639 = -378
-378 ÷ 639 = -0.5915492957746479
-0.5915492957746479 x 100 = -59.15%