U.S. energy firms this week continued to cut the number of rigs drilling for oil to the lowest in nearly six years, data showed on Friday, suggesting drillers were preserving cash as they evaluate spending plans as crude prices hover near 12-year lows. Drillers removed one oil rig in the week ended Jan. 15, bringing the total rig count down to 515, the least since April 2010, oil services company Baker Hughes Inc said in its closely followed report. That is 851 fewer rigs from the 1,366 oil rigs operating in same week a year ago. It was a slowdown in the pace of reductions as drillers cut on average 18 rigs per week in 2015 for a total of 963 oil rigs for the year. Despite the slowdown, several energy firms were still waiting for higher prices before increasing their drilling activities.