-49.1% is the change from 670 to 341
Calculation steps:
[( 341 - 670 ) ÷ 670] x 100 = -49.1%
Formula
Percentage change = [(341 - 670) / 670] x 100
Subtract the new number by the original number
341 - 670 = -329
-329 ÷ 670 = -0.491044776119403
-0.491044776119403 x 100 = -49.1%