Particularly in the 19th century, when economic conditions were difficult in Norway, tens of thousands of people migrated to the United States and Canada, where they could work and buy land in frontier areas. Many went to the Midwest and Pacific Northwest. In 2006, according to the US Census Bureau, almost 4.7 million persons identified as Norwegian Americans, which was larger than the population of ethnic Norwegians in Norway itself. In the 2011 Canadian census, 452,705 Canadian citizens identified as having Norwegian ancestry.