The hot new statistic oil traders are eyeing is 71 years old

HOUSTON (Bloomberg) -- This past Friday, oil traders were bent over their desks, staring at their screens, waiting for 1 p.m. New York time to see whether drillers extended their biggest-ever retreat from U.S. oil fields. (They did.) Oil futures spiked within minutes of the count, closing at the highest level in four days. ...»