As you aptly alluded to, in the province of clearance, where the goods are landed.... After that, we don't track where they go in the country.
There's a project in the national accounts where they try to measure interprovincial trade flows, but it's detached from that administrative data source.
In terms of improving the transshipment data, we're working with our colleagues at CBSA. We've put in some measures. They have penalties to try to really get at the issues of reporting, the whole under-coverage issue.
For the other part, we keep negotiating with our colleagues in the United States to get access to those in-transit documents from U.S. Customs and Border Protection. If we could get those, they would help us a lot.
As I mentioned earlier, we had access to them only twice. We had a one-week period in 2003 and found that there was about 90% under-coverage. We had a longer period in 1993-94, when we were looking at about a 65% under-coverage rate. So there is quite a bit of trade that's going sort of in-transit out of the country, which, based on our measures, we aren't accounting for.
What we do to sort of account for this is in the balance-of-payments-based series. We put in what we call an export under-coverage adjustment, which currently represents between 3% to 4% of total trade.
We're expecting that when we finish the latest study we've been doing on the marine ports, this number will come down. We don't know by how much, but we will react and adjust that export under-coverage adjustment.
So we are trying to add in at the aggregate level an accounting of what we believe is missing, in terms of exports on the balance-of-payments-based series.