3.3.3 Concluding remarks 73. Based on the statistical evidence presented above, it is difficult to estimate the total number of stateless persons living in the Netherlands. To do so would be to deny the significant inaccuracies in the available quantitative data. The current statistics only contain those stateless persons and persons of unknown nationality who have been registered by their municipalities. No statistical material is available on the number of illegal and unregistered stateless persons; they remain completely invisible. Recalling that in 2009 an estimated total of 97,000 illegal aliens lived in the Netherlands, the number of stateless persons among them could be substantial. Furthermore, people who have erroneously or unilaterally been attributed a nationality do not show up in statelessness-related statistics even though they may be stateless. The story of the boy born in the Netherlands to a Sri Lankan mother recounted just after paragraph 122 below is an example of this. 74. Coming up with a total tally of the number of stateless persons in the country is further complicated by the lack of clear and consistent registration guidance and practice. For instance, some 37 per cent of registered stateless persons are in all likelihood Moluccans with quasi Dutch citizenship. Children of parents born in Portugal make up another 9 per cent of all officially stateless persons in the Netherlands, but they can in principle acquire Portuguese citizenship whenever they so desire. Moreover, as the GBA is not automatically updated when they do acquire Portuguese nationality, many of these individuals may no longer be stateless. Another 3 per cent of registered stateless persons are of Cape Verdean origin, to whom the same reasoning applies. All in all, this leaves us with less than a thousand registered stateless persons (around half of the original total) who are likely to be stateless. Although this is a relatively small figure, it is important to realize that a clear majority of these persons are still children and that most have been born in the Netherlands. Many do not hold a residence permit. A specific inquiry into this group in particular seems warranted, as at present it appears as if, among other legal instruments, the 1961 Convention and the Convention on the Rights of the Child are not respected in all cases. 75. Finally, employing the available statistical material, it is impossible to gauge exactly how many persons are stateless within the category “nationality unknown”. What we do know is that children are manifestly present among this group. Moreover, taking the heavy burden of proof upon the applicant to be registered as a stateless person into account, combined with the fact that stateless persons are often inherently unable to meet these stringent documentary requirements, it is probable that a considerable number of stateless individuals are hidden within the label “nationality unknown”. The group of persons whose nationality is unknown and who do not hold a residence permit either (comprising 10,493 individuals) may be at particular risk of statelessness, or at least unreturnability. in the Netherlands 33