Number of cigarrettes smoked by Dutch smokers per day from year 1988 to 2000:
a) according to gender – male and female.
b) according to age group – 20-44, 45-64, and 65 older.
a) square – male, cross – female
b) X – 20-44 years old
Y – 45-64 years old
Z – > 65 years old.
Part I: % of Dutch people are smokers
Part II: % of Dutch smokers smoke more than 20 cigarrettes
Part III: Number of cigarrettes per Dutch smokers per day