format
A data frame with 150 observations on the following 5 variables:
rl{
id: Subject identifier (numeric)
year Calendar period, 1931: 1931--35, 1936: 1936--40,
...
age Age class: 10: 10--14, 15:15--19, ...
lung Lung cancer mortality rate per 1,000,000 py.
nasal Nasal cancer mortality rate per 1,000,000 py.
other All cause mortality rate per 1,000,000 py.
}source
From Breslow and Day, Vol II, Appendix IX.