Sum Non Adjacent Cells, Ignore Error Cells

[MamaStacia]

Hello, Thank you for your help. I have a formula that works fine as long as there are not any errors in the cells it's calculating. If there are any errors it returns a #N/A error. I am trying to find the average of 2 columns monthly without averaging averages (which would be incorrect data). The only thing that is different in the 2 formulas below is I added +(D14/D14) and D14 & E14 have a vlookup #N/A error since it's for Aug which doesn't have data yet. Is there an IFERROR, IFNA, or SUMIF function I can use with the formula below so I can set it and forget it for 12 months of data? The formula I tried wouldn't work.

Working Formula
=((D8/E8)+(D9/E9)+(D10/E10)+(D11/E11)+(D12/E12)+(D13/E13))/(COUNT(C8:C18)) = 59.1%

Error Formula
=((D8/E8)+(D9/E9)+(D10/E10)+(D11/E11)+(D12/E12)+(D13/E13)+(D14/E14))/(COUNT(C8:C18)) = #N/A

Tried Formula
=SUMIF(((D8/E8)+(D9/E9)+(D10/E10)+(D11/E11)+(D12/E12)+(D13/E13)+(D14/E14))/(COUNT(C8:C18)),">=0")

 

[MamaStacia]

Image of my spreadsheet for reference.

 

[CA_Punit]

So i have two Question

In the range D8:D14 if there is error in D14 how much count should (COUNT(C8:C18)) generate. 7 count or 6 Count (Ignoring Error)

can you go with other formula (instead of manually entering the ranges each and every time)

 

[MamaStacia]

The count excludes any cells with errors (6). I would be happy to go with any formula that would work preventing an average of averages. The end result is the Average % of Net Hours to Total Hours over months containing data which will auto update as data is added to the list each month. AVERAGEIF(E8:E18,">=0") works perfectly with the whole numbers just not the %.

 

[MamaStacia]

Nevermind, reviewing the data row 13 was incorrect. Should have been 61.9%, 6.5 and 10.5 respectively. Correcting the data allowed for AVERAGEIF to work since it is an average of percentages not average of averages. Thank you for your help. Problem Solved!