format
A data frame with variables of both discrete and continuous
types.
FEV (Forced ejection volume),
Kol (Cholesterol),
Hyp (Hypertension (no/yes)),
BMI (Body Mass Index),
Smok (Smoking (no/yes)),
Alc (Alcohol consumption (seldom/frequently)),
Work (Working (yes/no)),
Sex (male/female),
Year (Survey year (1967/1984)),