Let me think...
The IOM is as usual a couple of years late with recession. Thus numbers are depressed now compared to the downturn in th UK over the last couple of years.
We've had the Ash cloud, a couple of periods of very unseasonal poor weather and a new larger ferry with aggresive marketing to compete.
The falling of TT and Easter was different to last year and didn't help as it split figures between months too.
So overall, to be near enough to last year is not too bad. easyJet buggering about has also skewed figures on routes, they are not playing the same game as everyone else so it confuses things still further.
As to excessive waste at the airport, there are not too many culprits....just the usual suspects.