strong public interest in the new dollar, from the very start the coin still failed to circulate. In 1976, a Treasury study done in conjunction with a private-sector firm found that the Eisenhower dollar had a near-100 percent attrition rate, that is, almost always, a coin was used in only one transaction, and then stopped circulating (by comparison, the attrition rate of the quarter was close to zero). This was because of the coin's bulky size and weight, and the lack of potential uses for it. Even so, it was successful in quickly replacing private-issue tokens in Nevada casinos. According to numismatist Randy Camper, over 70% of "circulating" Eisenhower dollars were used in casinos. Although the vending machine industry lobbied for the Eisenhower dollar, few machines were modified to accept the coins. Lange recalled, "The fact is that these coins never circulated outside of casinos and nearby areas, and I don't recall ever seeing a vending machine that accepted them." Production Early years (1971–1974) The Mint struck over 125 million of the Eisenhower dollars in 1971, more than doubling its largest annual production for a dollar coin. Despite an increased mintage in 1972 to over 170 million, and despite what COINage magazine termed "near-heroic measures on the part of the Mint", the piece did not circulate. In a 1974 article for COINage, numismatist Clement F. Bailey noted, "the circulation value of the coin has been nil". Many Eisenhower dollars were put aside as souvenirs by non-collectors. Nevertheless, the silver coins sold so well that in October 1971, Mint Director Brooks warned that orders for 1971-S proof dollars would not all be filled until well into 1972. She ascribed the delay to the large public demand and to production difficulties which she indicated had been corrected. More than 11 million of the 1971-S silver pieces were sold, in proof and uncirculated, with over 4 million in proof. In May 1972, Treasury Secretary John Connally, testifying before a Senate committee, described the profits the Mint had made on the silver version of the Eisenhower dollar as "just unconscionable", with the average profit on a silver coin at $3.89, and expected to increase as production became more efficient. Mint officials felt that reducing the price would anger those who had already purchased the pieces. The 1972 silver pieces were again struck at San Francisco. Sales dropped considerably, to just under 2.2 million specimens