Bloomberg: Oklahoma registered one of its biggest earthquakes Saturday even after state regulators have beefed up limits on disposing oilfield waste and the rate of tremors had started to slow somewhat from unprecedented levels last year. The tremor in central Oklahoma was felt from Texas to Illinois, measuring 5.6 in magnitude and tying a state record set in 2011, according to the U.S. Geological Survey. The number of earthquakes measuring 3.0 or higher reached 890 last year, followed by 375 this year through...