There is a slight difference between these two phrases:
ZZZ 2014 YTD sales are up through Q3
ZZZ sales are up in the first three quarters of 2014
The difference is that in the first, the total sales for the first three quarters is compared to the previous year's first three quarters in total. The second is unclear, but suggests that you may be comparing each quarter by quarter and have an increase in each of them separately (Q1 2014 vs Q1 2013, Q2 2014 vs Q2 2013, and Q3 2014 vs Q3 2013). Include YTD as well as the specific end point (
through Q3) to be the most clear if that's what you mean.
Also, if you mean Fiscal Year not Calendar Year, it is slightly more clear to specify that:
ZZZ FY 2014 sales are up through Q3
Finally, if you want a more nice 'reading' sentence, I would put it like this:
ZZZ sales are up for the fiscal year 2014 through the third quarter.
Through the third quarter of fiscal year 2014, ZZZ sales are up.
In both cases "Through" makes it clear that you mean the entire period and not each period separately.
If you specifically mean quarter by quarter, on the other hand, then say
ZZZ sales are up for each of the first three quarters of 2014
or something similar to that.