The number of shareholders of a credit union is limited and formalized by a list. Limit of the number is defined by the assembly and such assembly establishes the charter. In the U.S. credit unions timely and full repayment of loans is a common phenomenon. Unpaid and delinquent loans are not more than 3% of their amount. Until the 70's there was a proliferation of the U.S. credit unions due to the increase of their number and the number of shareholders, although it must be acknowledged that there was also and a qualitative growth. Historically, credit unions have grown from the experience of credit cooperatives, but they took the experience of organizations of mutual aid of citizens by moving methods of social self-protection from labor and toward consumption. Credit unions historically formed as a special form of social support, initially taken upon themselves the social mission of protecting the interests of citizens in the field of financial services.