Gypsies and Travellers (Hertfordshire)

The Government’s figures seem to show that in July 1979 there were 1,000 caravans on unauthorised sites and 2,500 on socially rented authorised sites. However, in July 2005 there were 5,000 caravans on unauthorised sites and 6,500 on socially rented sites, as well as an additional 2,000 on Travellers’ own land and a further 2,000 authorised private sites. Does that not show that increasing the number of authorised sites does not stop the numbers on unauthorised sites from increasing?