Double-digit growth and growth that massively fluctuates are generally signs of a small airport. At Dublin's current scale, neither is hugely likely.
If Aer Lingus/Ryanair were to add and A320/B737 at Cork or Shannon, they are likely to get double-digit growth (and more than likely no growth the following year as another airframe is very unlikely). If the same happens in Dublin it may add 1% to the figures.