Population numbers can be hard to interpret, but this article gives it a shot regarding the U.P.
Excerpt: A curious, century-old population trend in Michigan’s Upper Peninsula shows a yo-yoing cycle of growth and decline every 20 years.
The U.P. grew slightly in the 1910s, 1930s, 1950s, 1970s, 1990s and, just like Old Faithful, is growing early in the 2010s, according to data from the U.S. Census. It declined slightly in the other decades, including a loss of 2 percent from 2000 to 2010.
The whole story can be found here
Source: Great Lakes Echo