Wind power last year continued its climb toward becoming a significant U.S. energy source, contributing 4.1 percent of the electricity generated in the country, up from 3.4 percent in 2012, according to figures released by the industry Wednesday.

That share still may sound puny, but consider that in 2000, wind was at a barely perceptible 0.1 percent, and it wasn’t until 2008 that it edged over the 1 percent mark. So it’s been on a steep growth trajectory lately, and in some states, wind is now a major producer: More than a quarter of South Dakota’s and Iowa’s electrical generation came from wind in 2013, and nine states – including Minnesota, Colorado and Oregon – were over 12 percent.

This government data,