A/HRC/4/29 page 20 directly hiring private teachers to provide instruction, without involving the educational community. It is, furthermore, clear that the absence of institutional change leads to the creation of groups of parents who prefer a system of special education for their children. Statistical information 66. Among the responses received by the Special Rapporteur, there is a conspicuous lack of statistical data on the number of persons with disabilities, and even less information on the number of persons with disabilities enrolled in school. Moreover, the variety of methods of counting and statistical measurement makes it extremely difficult to compare data. Comparability of data is particularly important for understanding the seriousness of the problem of educating persons with disabilities. 67. There is also very little statistical information on school abandonment or dropout rates for children and young people with disabilities, and there are practically no statistics that compare these rates with those for students without disabilities. Nevertheless, preliminary data indicate that the dropout rate for children with disabilities is comparatively higher than for children without disabilities. This phenomenon is attributed to the stigmatization to which children with disabilities are subjected, poor teacher training, limited resources and the inadequacy of educational infrastructures. 68. Similarly, there is little information on the academic success or failure (absolute and comparative) of children and young people with disabilities. 69. It would be particularly interesting to know the institutional movements of the disabled population over a relatively significant period of time. In some countries this population has been transferred, in whole or in part, from special education to regular education systems, and it is probable that the enrolment rate was initially high. However, it is important to know what happened and what happens when this population drops out of a system that has not been able and/or has not known how to include it. If, as has occurred in some countries or in some regions of some countries, special education institutions have totally or partially disappeared, where has the disabled population gone? Support services and teacher training 70. The inclusion measures listed in the responses to the questionnaire sent out by the Special Rapporteur refer mainly to institutions providing support and assistance to teaching staff as part of the process of integrating persons with disabilities into mainstream schools. However, the vast majority of responses point out the precariousness and inadequacy of these programmes, provisions and policies. In Western European countries, inclusion programmes are more systematic and structured, while in Latin America and Africa they are limited to isolated strategies that are rarely implemented. 71. Most of the countries and organizations surveyed refer to the need to invest in the training of regular teachers for children with special needs, through educational institutions that provide both initial training and specialization courses and in-service training.