Actually there has been a large increase in quakes per year since 1980.
Take a look
http://forums.overclockers.co.uk/showpost.php?p=15767475&postcount=27
No, all that shows is that seismometers picked up more quakes... To get a real understanding of whether the number of quakes has increased you need to correlate that data with the number (and increased sensitivity) of seismometers.
General scientific opinion is that the number of earthquakes has stayed broadly the same over the mid-long term (what I mean by that is evening out the yearly anomolies and taking trends of 10 years at a time).
This is a problem that plagues science, or at least popular science. People need to realise raw data (and that's what the above is) doesn't mean anything. It needs to be analysed in certain ways to actually be of any use. You can't just look at a load of raw data and go "Oh, look!"
EDIT: Firstly, where was that data actually from? Second, in fact the only odd thing about those numbers on their own is the abnormal number of 8+ magnitude earthquakes. Yes there is a slight increase of measured earthquakes but measuring over a 30 year period, not geologically significant in the slightest.
Watching those tremor charts is like really crappy foreplay. Katla is such a tease.
Haha