The June 1999, Kansas State University publication, Kansas Home*A*Syst-An Environmental Risk-Management Guide for the Home, has a pie graph (Fig. 4.8) with the following average household water usage rates:
Toilet - 28%
Clothes washer - 22%
Shower - 21%
Faucets - 12%
Bath - 9%
Toilet leaks - 5%
Dishwasher - 3%
There is no detail as to whether these averages are for the U.S. or Kansas. There is an acknowledgment that the chapter was based on material written by Barbara Kneen Avery, College of Human Ecology, Cornell Cooperative Extension.
This publication can be viewed on the following Web site:
Choose the link, "Environmental risk management guide for the home" and go to chapter 4, page 43 of the document. Hope this helps.
Barbara Johnson, PE