Table 1.

Number of subjects and mean density by diagnostic category

Diagnostic category	Number of subjects	Mean (SD) percent density
No cancer	9,737	33.1 (20.6)
Cancer at 1996 screen	82	42.9 (17.8)
Interval cancer < 1 year	7	50.3 (28.1)
Interval cancer 2 to 3 years	42	34.2 (22.0)
Cancer at subsequent screen	96	34.5 (21.2)
Cancer thereafter	84	42.4 (24.3)
Total	10,048	33.3 (20.7)

SD, standard deviation.