-51.79% is the change from 670 to 323
Calculation steps:
[( 323 - 670 ) ÷ 670] x 100 = -51.79%
Formula
Percentage change = [(323 - 670) / 670] x 100
Subtract the new number by the original number
323 - 670 = -347
-347 ÷ 670 = -0.517910447761194
-0.517910447761194 x 100 = -51.79%