According to new data from the SBA, an estimated 552,600 new employer firms opened for business and 660,900 firms closed shop in 2009.

The agency's Office of Advocacy provided an update of small businesses statistics. Among them, seven out of 10 new employer firms survive at least two years, half at least five years, a third at least 10 years, and a quarter stay in business 15 years or more. In 2009, there were 27.5 million businesses in the United States.

Small businesses rely heavily on owner investment and bank credit, averaging about $80,000 a year for young firms, the SBA said. Startups rely about equally on owners' cash injections into the business and bank credit while young firms receive about three-quarters of their funds from banks via loans, credit cards, and lines of credit. One-tenth of startups and about a third of young firms do not use capital injections.