The economy of Canada is a highly developed market economy. It is the 9th largest GDP by nominal and 15th largest GDP by PPP in the world. As with other developed nations, the country's economy is dominated by the service industry which employs about three quarters of Canadians. Canada has the third highest total estimated value of natural resources, valued at US$33.2 trillion in 2019. It has the world's third largest proven petroleum reserves and is the fourth largest exporter of petroleum. It is also the fourth largest exporter of natural gas. Canada is considered an "energy superpower" due to its abundant natural resources and a small population of 37 million inhabitants relative to its land area.