You cannot include 2014 income as CIC is not asking for it in 2015 PGP applications. So no point in submitting your 2014 paystubs, IE benefits statements (documents not accepted by CIC) as 2014 NOA won't be sent until you filed taxes for 2014 in year 2015. By the time you get 2014 NOA, the 2015 PGP would be reached. The cap in 2014 was reached sometime in 3rd week of Jan. This is usually due to a lot of applications being returned: missing signatures, scanned signatures, not meeting LICOs as required, etc, etc. So this people who got their applications returned won't make the same mistake twice again. I would not be surprised that the cap would be reached by the end of the first week of Jan, if not, second week at the latest.
If you do not meet 2011 LICO, you would have to wait until Jan 2016. If you do not meet 2012 LICO, apply in 2017, etc. Basically as long as you have proof of meeting 2011, 2012, and 2013 LICO with option C printouts or NOAs you qualify to apply for 2015 PGP. You run the risk of losing your qualification to sponsor your parents if you fail to meet LICO of 2014, 2015, future LICO until your parents land. CIC will likely to be asking for all Option C printouts from time of application to time your parents land. If they see you did not meet the LICO in any of the given year, CIC can deny your parent PR.