Interesting:

http://www.newswire.ca/en/releases/a.../19/c9988.html

OTTAWA, Feb. 19 /CNW Telbec/ - NAV CANADA today announced its traffic
figures for the month of January 2009 as measured in weighted charging units
for en-route, terminal and oceanic air navigation services, in comparison to
the last fiscal year.
The traffic in January 2009 decreased by an average of 6.3 per cent
compared to the same month in 2008.
Fiscal year-to-date traffic was 3.4 per cent lower than in fiscal year
2008. NAV CANADA's fiscal year runs from September 1 to August 31.
Weighted charging units represent a traffic measure that reflects the
number of flights, aircraft size and distance flown in Canadian airspace.
These traffic figures are also available in graph form on NAV CANADA's
web site at www.navcanada.ca.