Sample year
  1987 p 1997 p 1997 p 1987
Age group, years 50-60   50–60   60–70   60-70
≤10 mm n=10 n.s. n=33 n.s. n=30 <0.05 n=16
  13.6%   18.6%   24.8%   13.3%
10–20 mm n=32 n.s. n=90 n.s. n=61 n.s. n=50
  43.2%   50.8%   50.4%   41.7%
>20 mm n=32 0.06 n=54 n.s. n=30 0.001 n=54
  43.2%   30.6%   24.8%   45.0%
Σ n=74   n=177   n=121   n=120
n.s., not significant
Table 3: Distribution of three tumor size intervals of two age groups in 1997.