population of the country. The highest number came from Bosnia and Herzegovina, followed by immigrants from Serbia, North Macedonia, Croatia (which has since joined the EU itself) and Kosovo. In April 2019, there were 143,192 foreign citizens living in Slovenia, representing 6.87% of Slovenia's population. The number of people migrating to Slovenia has been steadily rising from 1995; and the rate of immigration itself has been increasing year-on-year, reaching its peak in 2016. Since Slovenia joined the EU in 2004, the yearly inflow of immigrants has doubled by 2006 and tripled by 2009. In 2007, Slovenia was one of the countries with the fastest growth of net migration rate in the European Union. Religion Traditionally, Slovenes are predominantly Roman Catholic. Before World War II, 97% of Slovenes declared as Roman Catholics, around 2.5% were Lutheran, and only around 0.5% belonged to other denominations. Catholicism was an important feature of both social and political life in pre-Communist Slovenia. After 1945, the country underwent a process of gradual but steady secularization. After a decade of severe persecution of religions, the Communist regime adopted a policy of relative tolerance towards the churches, but limited their social functioning. After 1990, the Roman Catholic Church regained some of its former influence, but Slovenia remains a largely secularized society. According to the 2002 census, 57.8% of the population is Roman Catholic. As elsewhere in Europe, affiliation with Roman Catholicism is dropping: in 1991, 71.6% were self-declared Catholics, which means a drop of more than 1% annually. The vast majority of Slovenian Catholics belong to the Latin Rite. A small number of Greek Catholics live in the White Carniola region. Despite a relatively small number of Protestants (less than 1% in 2002), the Protestant legacy is important because of its historical significance, since the bases of Slovene standard language and Slovene literature were established by the Protestant Reformation in the 16th century. Nowadays, a significant Lutheran minority lives in the easternmost region of Prekmurje, where they represent around a fifth of the population and are headed by a bishop with the seat in Murska Sobota. Besides these two Christian denominations, a small Jewish community has also been historically present. Despite the losses suffered during the Holocaust, Judaism still numbers a few hundred adherents, mostly living in Ljubljana, site of the sole remaining active synagogue in the country. According to the 2002 census, Islam is the second largest