M.E.
Thanks for starting this back up. Hopefully we can get a sticky on this so its always easy for every one to find.
There are some great ideas here. Since for some of us centuries are a challenge and trying to do one a month is even more of challenge. I have an idea combined some of the additional thoughts here. Since you can always go back in and edit the list. To the right of the name in brackets we could put 1/1 for anybody completing a century in January. And to use ronjon as an example, in March he would be 1/3 and at year end he would be 10/12. That is still a great accomplishment.
The goal is at year's end is to 12/12 or for some of us that have month or two where they can't get a century, as close to 12/12 at the end of the year. For the distance maniacs who complete more than one century a month, only one counts.