If you participate in a 401k provided by Pension Systems Corporation (i.e. 401k Easy, Open Architecture 401k, 401k Fee Disclosure, 401k Network, etc) much of the investment profile information available in this website is included in your personal online 401k statement.
If you participate in another provider's 401k, you can still use this information to refine your 401k contribution and investment choices. With 401k Census you can easily compare your 401k's profile to others in your demographic group.
Average 401k Savings by Age