I know:

The dates I am going to be working, the month of December.
The Total number of Welds I need to complete, 2000.
The Date I start at 0 welds, 12/1/06
The Date I think I'll be half way done, 12/12/06
The date I think I'll be 90% done, 12/26/06
The Date I think I'll finish, 12/31/06

How do I fill in the cumulative data between my "known" values?
Is there a way I can apply a log rhythmic distribution curve to my total to
calculate them all?