A/HRC/11/9 page 21 attention should be paid to particularly vulnerable groups of children, such as orphans, street children, children with disabilities, and child-headed households, who are detached from adult-headed households and often are omitted from CTP. C. Persons with disabilities 84. Disability is often both a cause and consequence of poverty. There are approximately 650 million persons with disabilities in the world - that is 10 per cent of the global population. An estimated 80 per cent of these persons live in developing countries, many in poverty. In both developed and developing countries, evidence suggests that persons with disabilities are disproportionately represented among the poor and tend to be poorer than their counterparts without disabilities.29 85. The Convention on the Rights of Persons with Disabilities, article 2 of the Convention on the Rights of the Child and the principle of non-discrimination in international human rights law oblige States to ensure that persons with disabilities enjoy all human rights on an equal basis with others.30 It recognizes the right of persons with disabilities to an adequate standard of living for themselves and their families and to ensure their realization without discrimination on the basis of disability. It also recognizes the obligation of States to ensure their right to social protection without discrimination. States must ensure access of persons with disabilities to social protection and poverty reduction programmes and the right of those living in poverty and their families to have access to assistance from the State with disability-related expenses, including financial assistance (article 28, Convention on the Rights of Persons with Disabilities). 86. The above Convention also specifically recognizes the importance of international cooperation and its promotion of the realization of the rights of persons with disabilities: it stipulates that international cooperation measures should be inclusive of, and accessible to, persons with disabilities, and facilitate and support capacity-building (art. 32). 87. Disability grants must be part of a broader social protection system that should include a comprehensive set of measures, from inclusive access, to education and health services to facilitate employment. A key concern should be the adequate standard of living and social inclusion of persons with disabilities. 88. Today, there is a lack of data on the impact of CTPs on persons with disabilities and their families. States should strengthen the collection of data on the impact of CTPs on persons with disabilities as well as in regard to the type and degree of disability in the population. 29 E/CN.5/2008/6, para. 2. 30 See Committee on Economic, Social and Cultural Rights, general comment No. 5 (1994).