These charts show the new user signup, tunnel and subnet requests per month.
Every single signup and request is accounted for in these graphs, this is all the data that is there, no more, no less. The date reflects the date of when an account, tunnel or route was created, but with the current state. This data is made public, like other statistics, so that everybody can view the status of the project.
The SixXS system, unless specifically requested by the user, retains full details of every object created in the system, this to aid in traceability and for statistical reasons. The data for the tunnels&routes of the former IPng PoP were purged and as these graphs are generated in realtime, the information from 2000-2002 is mostly empty. There are quite a few number of users still from that time though and they are still visible in the user graphs.
Non-verified are account requests where an email was sent because the user signed up, but then didn't verify the account. Bounced indicates the number of accounts that at some point in time had a bouncing email, and thus were set to bounced. Deleted shows the number of accounts that users deleted themselves. Disabled indicates the number of accounts that were disabled because of abuse or other such reasons.