In British Columbia, the vouching provision was used more in our most northern electoral district, the district of Stikine, than in any other electoral district. We certainly don't have the numbers that David is talking about, but about 3.5% of all voters in Stikine were vouched for, and in some of the urban districts, it would be less than one-half of 1%. There are certainly differences across the province, and as you're suggesting, it's not randomly distributed. People in the more remote areas are evidently more challenged to provide their proof of identity with a single document.
On March 25th, 2014. See this statement in context.