Despite market volatility, annual contributions to IRAs continued to increase for tax year 2012, according to an analysis of IRA data by Fidelity, one of the largest IRA providers.

Fidelity found that contributions have increased an average of 5 percent over the past four years, reaching $4,108 for 2012. Contributions for tax year 2012 can be made until April 15. Fidelity says it traditionally receives 45 percent of IRA contributions within the last four weeks before the tax filing deadline.

Contributions increased across the board for all age groups but rose more for older investors––up to an average of 6 percent for those in their 60s––from $4,674 in 2009 to $4,960 in 2012.

The lowest contributions were made by those in their 20s, reaching $3,235 in 2012 from $3,154 in 2009.

Those investors combining an IRA with a workplace 401(k) or 403(b) account had the best retirement savings with an average of $225,600 compared to the average Fidelity 401(k) balance alone of $77,300.

The popularity of Roth IRAs is greater among younger investors, with 86 percent of investors in their 20s putting money in Roth IRAs, according to Fidelity. That percentage drops to 46 percent for investors in their 60s.