Creating Year to Date formula using Vlookup or sumif and exclude #N/A

[CassidiC12]

Hi everyone,
I have a spreadsheet that has a different tab for each month and a YTD tab. Each month has a list of the associates and the metrics we are tracking each month. See below for January, sorry if it's not in a good reading format.

Associates Escalations % of Esc CrAgmt% Kept Prod. W/DN % CCT Evals
Beasley, Jennepher 2 1.37% 53% 98% 0
Beeson, Donna 11 1.67% 57% 88% 3
Brockman, Prisicilla 2 1.60% 67% 86% 0
Chavez, Lori 4 0.46% 58% 93% 3

For my year to date tab, I need to add up all the Escalations for Jennepher Beasley, but I can't guarantee that Jennepher Beasley will be on the same line in each Month tab. That's why I was trying to do a Vlookup or SumIF function. However, I'm having trouble with excluding #N/A for the months that aren't completed yet. However, the function did work for Escalations, just not % of Esc. the reason I think is because in Jan-Dec Escalations is using a CountIF formula and % of Esc is using a vlookup. Would that make a difference? The formula I used for Escalations is below:

=SUM(SUMIF(Jan!$A$3:$X$64,'2013 Team YTD'!A5,Jan!$B$3:$B$64),SUMIF(Feb!$A$3:$X$64,'2013 Team YTD'!A5,Feb!$B$3:$B$64),SUMIF(Mar!$A$3:$X$64,'2013 Team YTD'!A5,Mar!$B$3:$B$64),SUMIF(Apr!$A$3:$X$63,'2013 Team YTD'!A5,Apr!$B$3:$B$63),SUMIF(May!$A$3:$X$64,'2013 Team YTD'!A5,May!$B$3:$B$64),SUMIF(Jun!$A$3:$X$64,'2013 Team YTD'!A5,Jun!$B$3:$B$64),SUMIF(Jul!$A$3:$X$64,'2013 Team YTD'!A5,Jul!$B$3:$B$64),SUMIF(Aug!$A$3:$X$64,'2013 Team YTD'!A5,Aug!$B$3:$B$64),SUMIF(Sep!$A$3:$X$64,'2013 Team YTD'!A5,Sep!$B$3:$B$64),SUMIF(Oct!$A$3:$X$64,'2013 Team YTD'!A5,Oct!$B$3:$B$64),SUMIF(Nov!$A$3:$X$64,'2013 Team YTD'!A5,Nov!$B$3:$B$64),SUMIF(Dec!$A$3:$X$64,'2013 Team YTD'!A5,Dec!$B$3:$B$64))