17 | PROTECTING STATELESS PERSONS FROM ARBITRARY DETENTION IN BULGARIA In addition to the above numbers, the Ministry of Interior provided statistics with regard to foreigners of ‘unknown citizenship’ who reside lawfully in Bulgaria (see Table 5).67 Table 5: Number of residence permits issued to persons of ‘unknown citizenship’ in Bulgaria by year Year Continuous residence Permanent residence Long-term residence 2007 - - - 2008 4 1 - 2009 13 7 - 2010 6 15 - 2011 8 18 - 2012 11 13 - 2013 10 16 - 2014 5 19 - 2015 2 8 - 01 January – 31 May 2016 1 1 - While it was requested, no statistical data was provided with regard to the number of stateless persons and persons of ‘unknown citizenship’ who have been issued return (removal) decisions and who reside in Bulgaria. As noted above in the report, the Law on Bulgarian Citizenship (Article 14) provides that stateless persons are entitled to submit an application for Bulgarian citizenship once they have completed three years as holders of a permanent residence permit. In reply to a freedom of information request, the Ministry of Justice provided the number of stateless persons who have acquired Bulgarian citizenship by naturalisation (see Table 6 below).68 Table 6: Number of stateless persons who have acquired Bulgarian citizenship by naturalisation on the ground of Article 14 of the Law on Bulgarian Citizenship by year Year Number of stateless persons who acquired Bulgarian citizenship 2007 8 2008 19 2009 30 2010 19 2011 24 2012 34 2013 12 2014 12 2015 17 01 January – 31 May 2016 5 The above data might be interpreted as meaning that once stateless persons are allowed to reside lawfully in Bulgaria, their integration - the utmost legal expression of which is the acquisition of the host country nationality - is quite successful. At the same time, there is no data with regard to the number of irregularly residing stateless persons in Bulgaria, who are particularly vulnerable to (arbitrary) detention.