Complex sentence: In May 2012, the United States Department of Interior released updated regulations on fracking; however, Guggenheim Washington Research Group found that only about 5% of the shale wells drilled in the past 10 years were on federal land.
Split into simpler sentences: In May 2012, the United States Department of Interior released updated regulations on fracking, for wells on federal lands. However, Guggenheim Washington Research Group found that only about 5% of the shale wells drilled in the past 10 years were on federal land.