Overall participation rates in US retirement plans increased from 30% in 2003 to 34% in 2005, however, public sector plan participation continues to lag behind 401(k) plans which average 70% participation. Participants who are invested in three or more asset classes rose from 19% in 2001 to 39% in 2005. Average annual contributions increased by 8% to 20% or from $3,500 in 2003 to almost $3,800 in 2005 among all participant age groups. Those aged 18-25 increased their average annual contributions by 20% since 2003, compared to a range of nine to 17% in other age groups. Almost 30% of participants who are ages 18-25 selected an asset allocation option (lifestyle and lifecycle funds) as their single investment choice for ongoing deferrals, showing an understanding of the need to diversify investments, compared to a range of 3% to 18% for all other age groups.