Economic recovery eventually allowed Argentina to offer large-scale debt swaps in 2005 and 2010; the first brought 76% of bonds out of default and the second, 91.3%. The terms of the debt exchanges were not accepted by all private bondholders; the holders of around 7% of the defaulted bonds - known as "holdouts" - continued to seek full repayment. The IMF initially lobbied for the holdouts until Argentina's lump-sum repayment to the IMF in January 2006. Individual creditors worldwide, who represented about one third of this group, mobilized to seek repayment following the default. Among the most prominent were Task Force Argentina, an Italian retail bondholder association; and Mark Botsford, a private U.S. retail bondholder; and Kenneth Dart, who unsuccessfully sued in 2003 to be paid $724 million for bonds purchased in 2001 for $120 million. Dart renounced his U.S. citizenship in 1994 for tax avoidance purposes, and his interests in Argentina became the focus of tax evasion charges in 2013. Italian nationals had become the largest group of foreign retail investors in Argentine bonds when during the 1990s, banks in their country purchased $14 billion in bonds and then resold them to nearly half a million investors; the vast majority rejected the first swap but accepted the second.