posted price of oil
... that between 1957 and 1972, the market price of oil was less than the posted price of oil?
... that between 1957 and 1972, the market price of oil was less than the <b id="mwA8U"><a href="./Posted_oil_price" id="mwA8Y" rel="mw:WikiLink" title="Posted oil price">posted price of oil</a></b>?