what is your average water bill per year

I have been looking at our water bills. We have three people in the house and have a water meter which they read when they can be bothered. Most of the time it is once a year or once yevery two years. We are paying £50 direct debit each month which seems a lot to me for three people living in the property. It is a pitty you cannot do what you do with electirc bills where you can swap companies, but with water each area has their own company