That's a pretty awful figure for March. While February could be put down to the Manx2 crash, the same can't be said for March.
The best you could do is say that because Easter was at the start of April last year the 2010 figure includes some Easter traffic.
April should be a bit better as Aer Lingus have more capacity than last year (same number of A320s and one more ATR for April) and Easter puts all its traffic into April this year.
Now we have to see if the capacity is filled.