“Nationally, this week’s plunge marked the third-biggest one-week drop in the history of the rig count, compiled by oilfield service company Baker Hughes since 1987.”
Hughes Tool began the weekly rig count in the late 1940’s. 1987 might have been about the time they merged with Baker
Baker Hughes was formed in 1987 with the merger of Baker International and Hughes Tool Company — both founded over 100 years ago when R.C. Baker and Howard Hughes, Sr. conceived ground-breaking inventions that revolutionized the fledgling petroleum era.
http://www.bakerhughes.com/company/about/about-baker-hughes-corporate-profile