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.