WEBENCH® Tools/LMZ31710: discrepancy Rset between WEBENCH and datasheet

Part Number:LMZ31710

Tool/software: WEBENCH® Design Tools

Hi,

I noticed a discrepancy for Rset between the datasheet and the WEBENCH design, for instance:

for Vout=1.8V,  datasheet Rset=715  but WEBENCH Rset=732

for Vout=3.3V datasheet Rset=316 but Webench Rset=309

why the discrepancy ? and which one is correct ?

thanks

phil