After dropping by nearly $2 trillion in the fourth quarter of 2018, U.S. retirement assets recovered to their previous levels during the first quarter of this year, according to a report released Wednesday by the Investment Company Institute (ICI).

As of March 31, total U.S. retirement assets were $29.1 trillion, up 7.4 percent from December, according to the ICI. Retirement assets accounted for an even third of all household financial assets in the U.S.

U.S. total retirement assets in the first quarter about equaled their $29.1 trillion total at the end of the third quarter 2018, according to the ICI.

The largest segment of retirement assets, totaling $9.4 trillion, reside in IRAs. A little under half of these assets, 46 percent, was invested in mutual funds.

The next largest sum is held in defined contribution plans, which contained $8.2 trillion in assets. Most of this money, $5.7 trillion, is in 401(k) plans, but $1 trillion is held in 403(b)s, with 457 plans, the Federal Employees Retirement System’s Thrift Savings Plan and other private-sector defined contribution plans accounting for a little under $1.5 trillion in assets.

Another $6.3 trillion is held in government-sponsored defined benefit plans, while $3.2 trillion is in private-sector defined benefit plans. Annuity reserves round out the total with $2.1 trillion in assets.

The ICI noted that while just $1.2 trillion is held in target-date funds, these assets have grown by 11.6 percent since the end of December. Almost all of the target-date fund assets, 87 percent, comes from retirement accounts.