According to the Melbourne Mercer Global Pension Index, which studies global pension systems on the three indices of adequacy, sustainability, and integrity, a major weakness has been found in the retirement income and pension systems in China, India and Indonesia. Meanwhile Singapore, with its Central Provident Fund (CPF), is the only Asian country to be featured in the top 10. European countries such as Denmark and the Netherlands took the lead. Suggestions have been made in Singapore to open the CPF to non-residents, who make up more than a quarter of the workforce.