Color balance with EOS 350D

I photographed a white piece of paper in full sunshine, at noon, in raw mode.
I cropped the center of the image, and developped it in 48 bits. Here are the stats reported by Iris on the center part:

Red: Moyenne : 667.6 Médiane : 671 Sigma : 14.6 Maximun : 742.0 Minimum : 413.0
Green: Moyenne : 1294.5 Médiane : 1310 Sigma : 35.4 Maximun : 1481.0 Minimum : 508.0
Blue: Moyenne : 1106.0 Médiane : 1114 Sigma : 26.0 Maximun : 1245.0 Minimum : 540.0

Taking the median, the RGB adjustments should be:

R: 1.95 (1310 /671)
G: 1
B: 1.18 (1310/1114)

or (reversed, to avoid overflowing on integers):

R: 1
G: 0.51 (671/1310)
B: 0.60 (671/1114)