During the late 1970s, prices quoted in terms of the Israeli currency, the shekel, rose so fast that grocery stores listed their prices in terms of the U.S. dollar and provided customers with dollar-shekel conversion tables that they updated daily. Although people continued to buy goods and services and make loans using shekels, many Israeli citizens converted shekels to dollars to avoid a reduction in their wealth due to inflation. In what way did the U.S. dollar function as money in Israel during this period?