How much does the Petroleum industry contribute to Canada's GNP?

I am doing a report for school on Husky Energy, which is a major oil company in Canada based in Calgary,Alberta. I need to do a section on the petrol industry as a whole in Canada. The Petroleum industry would include Oil,Butane,natural gas etc. Does anyone know how much this would contribute to Canada's Gross National Product in terms of percentages or raw numbers? Thanks!