Sample year
  1987 p 1993 P 1993 p 1987
Age group, years 50-60   50–60   60–70   60-70
≤10 mm n=10 n.s. n=18 n.s. n=22 n.s. n=16
  13.6%   18.2%   20.7%   13.3%
10–20 mm n=32 n.s. n=43 0.08 n=59 <0.05 n=50
  43.2%   43.4%   55.7%   41.7%
>20 mm n=32 n.s. n=38 <0.05 n=25 <0.001 n=54
  43.2%   38.4%   23.6%   45%
Σ n=74   n=99   n=106   n=120
  100%   100%   100%   100%
n.s., not significant
Table 1: Distribution of three tumor size intervals of two age groups in 1993.