Figure 4.

Trends in snus use by smoking group among women in the Västerbotten Intervention Programme 1990-2006. The lines show the prevalence of snus use in the three age groups - 40 years old (blue unbroken line), 50 years old (red broken line) and 60 years old (green dotted line), and by smoking history - never smoked (n = 22,505), previous smoker (n = 14,184) and current smoker (n = 10,407). Lines depict the mean value for the following periods: 1990-1994 (1), 1995-1998 (2), 1999-2002 (3) and 2003-2006 (4).