In 2002, Colorado experienced a drought and many towns on the front
range (a geographical district close to the Rocky mountains) issued
mandatory or voluntary water restirctions on outdoor watering. These
data are comparative water usage between 2001 and 2002 for five such
towns.
Arguments
References
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003),
Introductory Statistics for Engineering Experimentation,
Elsevier. (Appendix A)