These numbers actually understate the disparity by an order of magnitude. Canada is a sparsely populated country; there are more than nine times as many Americans as Canadians. That means that when adjusted for population, 20 times as many Canadians moved south in 2006 as Americans moved north.
In other words, a typical Canadian is 20 times more likely to decide to move to the U.S. than one of our folks is to move to Canada. Now, which country is the more attractive? For sure, don't ask ABC News as they clearly haven't a clue.