If we consider that the age for breast augmentation is between 18 and 45, there are 11,025,000 women in these age groups in France.
Each year, French surgeons place 35,000 pairs of implants (70,000 implants) which represents just over 0.3% of women in different age groups.
As the implants stay in place for about 10 years, we can consider that 3% of French women have breast implants.
It is in fact very variable from one region to another, from one socio-professional category to another, etc.
On the other hand the French woman often chooses small implants, so that after the surgery, you see that she has a nice body but you cannot guarantee her rack is siliconized.