sentences:  The number of U.S. commercial and savings bank institutions reached a peak of 14,495 in 1984; this fell to 6,532 by the end of 2010.The ten largest U.S. banks held nearly 50% of U.S. deposits as of 2011.Since the full amount of the deposits and debts of "too big to fail" banks are effectively guaranteed by the government, large depositors and investors view investments with these banks as a safer investment than deposits with smaller banks.