The graph shows the percentage risk of developing lung cancer for 75-year-old men who gave up smoking tobacco at an earlier age - Edexcel - GCSE Biology - Question 4 - 2013 - Paper 1

The graph illustrates that the later a person stops smoking, the higher the percentage risk of developing lung cancer by the age of 75. Specifically, as the age at which the men stopped smoking increases from 30 to 60 years, the percentage risk also increases.