-38.18% is the change from 647 to 400
Calculation steps:
[( 400 - 647 ) ÷ 647] x 100 = -38.18%
Formula
Percentage change = [(400 - 647) / 647] x 100
Subtract the new number by the original number
400 - 647 = -247
-247 ÷ 647 = -0.38176197836166925
-0.38176197836166925 x 100 = -38.18%