Sum the values and divide by a countif

So it would be like

Sum(B2:B51)/Countif(B2:B51,"0")

"RoadKill" wrote:

Okay, I have my lookup to zero but now realize that in the future that will
mess up my averages if a person actually gets a zero. So how can I get this
to just show an empty cell as that doesn't appear to impact the averages like
a zero will.

=IF(ISNA(VLOOKUP($B4, '3-25'!$A$2:$C$51,2,0)),0,VLOOKUP($B4,
'3-25'!$A$2:$C$51,2,0))

Thank you