There have been a number of significant changes. First of all, I would mention that 17 years ago CN was a crown corporation, and it was certainly not enjoying the level of productivity and efficiency it is now.
What's come out of that are a number of investments. If you look at their network, as an example, their reach into the United States, they purchased a railroad that essentially has a ring road around Chicago; 23% of all railroad traffic in the United States touches Chicago. It's a little bit like all roads lead to Rome; almost a quarter of all railroad tracks lead to Chicago. If you look at our map, you can see that both of our major companies travel through there.
CN was able to purchase a railroad that goes around Chicago, which allows them to transport freight to that critical area but also to not get caught in the traffic. Those kinds of investments have been possible because of deregulation, because of private sector investments they've been able to make.
In terms of the impact we have on the economy, I don't even like to use the $12 billion figure. Although it's a matter of public record, and it's an important figure, it belies the importance we play in the economy in terms of moving all of the goods for all of the customers and the different kinds of customers we have in this country.
If you look at the growth in Canada, the mining sector is the number one growing sector in Canada. Most operations would not be able to sell their product without rail, whether it's agriculture, potash, forestry, chemicals, or petroleum products now. Petroleum and chemicals account for more than 20% of rail traffic. It's an incredible story. Five years ago people would not have imagined we'd be moving so much product by rail, something that traditionally moves by pipeline. But we've had the flexibility. Companies like CP have done a great job of identifying opportunities, such as the Bakken, where they're moving shale oil.
Really, the story about freight rail today is about the future growth of this country in terms of our manufactured goods and our natural resources.
If I could take one more moment to tie it to one other thing—