Because of the chronic inflation experienced in Turkey from the 1970s through to the 1990s, the old lira experienced severe depreciation. Turkey has had high inflation rates compared to developed countries and suffered hyperinflation. From an average of 9 lira per U.S. dollar in the late 1960s, the currency came to trade at approximately 1.65 new lira per U.S. dollar in late 2001. This represented an average inflation of about 38% per year. Prime Minister Recep Tayyip Erdoğan had called this problem a "national shame". With the revaluation of the Turkish old lira, the Romanian leu (also revalued in July 2005) briefly became the world's least valued currency unit.