World vs E1 Straight Line Depreciation

My World experience is pretty limited, I thought I’d reach out to see if anyone could help shed some light on an issue I'm having.  

Straight line depreciation is calculating differently in E1 9.1 vs World A 9.2.  The client converted to E1 in July and for three years prior, depreciation was the same amount every month (with the exception of the first month).  Now, when we ran deprecation for the first time in E1, we are getting a different amount. 

Was there some basic functionality that changed between World and E1? 

Thanks!