Credit unions have increased membership base as well as deposits volume during the 12 months ending in March, according to a recent report from California-based Market Rates Insight.

Total membership increased to 91 million from 90.2 million at an average operating cost of $149 per new member acquisition, according to a statement. The average membership per credit union increased to 12,475 from 12,035.

The absolute increase in the average number of members per credit union was 439. The average same-store increase, which excludes mergers and acquisitions, in the number of members was 97 new members per credit union.

Total deposits (savings) at credit unions increased to $812 billion from $773 billion. The average deposits per member increased to $8,923 from $8,568. The greatest increases in deposits occurred in regular shares accounts (savings), which increased by $23 billion, followed by Money Market accounts up $15 billion and share drafts (checking) up $10 billion.

"The credit union segment of the banking industry is very dynamic," said Dan Geller, executive vice president, Market Rates Insight. "The increases in membership and in balance volume are an indication of broad appeal to and acceptance by the marketplace."