Also the older you are and the more you've worked the higher your account balance becomes. So once you have people with balances with $1M+ (which if you're actually saving for retirement you'll need), they'll be drawing much more per person.
* Enrollment
* Distribution
* Rollover
* Loan
* Panic due to market movements
* Asset allocation/rebalancing
The top three on that list are when you enter or exit a job so if you have been with the same company for those six years you likely would not have used customer service.
I do encourage you to sign up for a meeting with your 401(k) advisor if they come to your office and do those. It is good even as an excuse to look over where you stand.