How has the composition of the house of lords changed since 1997?

In 1997 the House of Lord was composed of 'Life Peers' who have been enobled because of their public work (retired civil servants, politicians, local councillors or prominent experts in science etc..)and the traditional 'hereditary peers' who occupied seats in the house of lords through accident of birth. As part of the reform process in 1999/2000, herditary peers are barred from speaking and voting in the house of lords.