Greg, seems like the analyses I've seen of BC's carbon tax consumption effect have only shown data through 2012, which is why I used 2012 as the base value.  If you use 2011 as the base, then through 2015 gross sales of gasoline have increased 15.6% in BC vs. 6% in Canada overall, although the latter figure would be slightly lower if BC wasn't included (as you point out).  I don't know why net sales of gasoline is more relevant than gross sales, since they define gross sales as "total sales of all road grades of gasoline for all uses, including off-road activities such as farming, forestry, construction or mining."  It doesn't say anything about exports but correct me if I'm wrong.  Otherwise you might be cherry picking a bit yourself?  It's a fairly simple table to look at and see which numbers have gone up or down, or you can download the spreadsheet.  In the end the consumption effect is a minor point, I-732 would still have essentially zero effect on future warming or ocean pH.