Total assets in IRAs are up 25% on average, according to a new Employee Benefit Research Institute report based on its own database.

At $732.9 billion, IRAs account for the lion’s share of all $13 trillion retirement assets in 14.1 million accounts in the United States.

Traditional IRAs, including those with assets rolled over from old employer-based plans, account for 67% of all IRAs, whereas Roth IRAs, in which investors pay taxes up front and withdraw income later tax free, make up around a quarter of the market. More than half or IRAs have at least $25,000 in them; the average IRA owner has $68,498 across one or more accounts. Men are slightly more likely to own an IRA than women, at 56.6% vs. 43.4%. Men also tend to have higher balances, averaging $91,063 to women’s $51,314.

The average annual contribution to an IRA isn’t much - $3,798 for traditional IRAs and $3,582 for Roth IRAs, which isn’t too surprising given that the annual contribution limit is $5,000 ($6,000 for those 50 and older). Only 7.2% of traditional IRA owners contributed to them in 2008; of that small minority, 42.4% maxed out their contributions. Most annual IRA money comes from rollovers, which in 2008 averaged $74,785.

Craig Copeland, senior research associate at EBRI, says the high rollover amount is a clear indication what business to target. When people change jobs, “the most important aspect is whether to leave their money where it is or rollover their 401(k) or pension plan lump sum into an IRA,” he says. Depending on the situation—low fees or a wide variety of options in the work plan—it may make sense for a person to leave their money at the old plan. However, “it might be more cost-efficient to go through with an IRA rollover, and that’s the sort of decision a  financial advisor can help with.”