In the U.S., credit unions have a clear organizational structure. All credit unions belong to one or the other parent credit union (there are 35 of them in the U.S.). 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. National Credit Union Insurance Fund was created by Congress in 1970 to insure deposits of credit union members in the amount of 100 thousand dollars. Credit unions encourage the proper use of shareholders savings, developing social programs (education, health, recreation, housing, etc.).