Mine is 63, too. I have under 50 hubs. With this lower number of hubs, I think my proportion of links to other hubbers is relatively high. It's interesting, though, because I think I have only created three or four deliberate links to other hubbers. I have used a tag-based rss feed that includes MOSTLY my own articles, but has one or two other authors' hubs mixed in. Wonder if that has something to do with it?