As no two people write the same way, nor do they write on the same topics or do the same promotion, to try and use another's growth stats to compare against your own seems a flawed comparison. Especially as HubPages too changes over time.
For example, when I first started, it was just over four years ago. The site was still in beta phase (being tested), there was no user forum, half the capsules we have now didn't exist, the follower feature was a few years from being invented, and the website on the whole had zero reputation.
How does that compare to when you started on this site just a month ago?