The reasons Insurers tend to offer lower prices for female drivers are that they generally do a lower annual mileage than male drivers so this reduces the amount of accidents. They tend to drive less agressively than males and have slower speed accidents eg car parks and reversing which are cheaper claims to repair for Insurers and often these claims involve no expensive personal injury claims.

The stats I have seen would indicate that if an equal mileage was driven by females they would have roughly the same amount of claims as males but they would still attract cheaper premiums as their accidents would be cheaper to settle due to the nature of their claims