tedster - 6:54 pm on Mar 8, 2012 (gmt 0)
google.ca : 37
google.com : 156
google.co.uk : 109
I usually find that such deep results are extremely unstable compared to page one results. For several years now, there seem to be waves of ups and downs that go through the deeper results on a daily (or even more than daily) basis.
I've been thinking that this is a sign of some kind of statistical testing, more than a true "this URL ranks at this position" verdict. Years ago, the deeper results were more stable. In fact during the monthly update period of young Google, they really were. Today, not so much.
Those three numbers also seem to say that there is less competition (or maybe "different" competition) for the three TLDs. Certainly .com would always be the most competitive, and I also think .co.uk is likely to top .ca in many markets.