A report by the Center for Budget and Policy Priorities and the Economic Policy Institute reveals that income inequality has increased since the 1980s. According to the report, the biggest cause of this growing income inequality has been the decline in wages for the 70 percent of workers who do not have a college degree. One of the main reasons for declining wages is the weakening of unions and the lack of effective labor laws to protect workers seeking to form unions. In fact, of the 10 states with the greatest income inequality, seven were states in the bottom half of union density, and six were right-to-work states. In 2005, according to the BLS, union members had median weekly earnings of $801, compared to $622 for nonunion workers, a 29 percent difference. A separate report released by the Center for American Progress shows the union advantage is even greater for Hispanic workers. The median weekly wage for Hispanic union members was $679 versus $428 for nonunion workers, a 59 percent advantage. Mexican-American women union members earn 70 percent more than their nonunion counterparts. BLS figures also showed that union membership rose by 213,000 in 2005, to 15.7 million members.