Official censuses with information on Transylvania's population have been conducted since the 18th century. On May 1, 1784 the Emperor Joseph II called for the first official census of the Habsburg Empire, including Transylvania. The data was published in 1787, and this census showed only the overall population (1,440,986 inhabitants). Fényes Elek, a 19th-century Hungarian statistician, estimated in 1842 that in the population of Transylvania for the years 1830–1840 the majority were 62.3% Romanians and 23.3% Hungarians. In the last quarter of the 19th century, the Hungarian population of Transylvania increased from 24.9% in 1869 to 31.6%, as indicated in the 1910 Hungarian census (the majority of the Jewish population reported Hungarian as their primary language, so they were also counted as ethnically Hungarian in the 1910 census). At the same time, the percentage of the Romanian population decreased from 59.0% to 53.8% and the percentage of the German population decreased from 11.9% to 10.7%, for a total population of 5,262,495. Magyarization policies greatly contributed to this shift. The percentage of the Romanian majority has significantly increased since the declaration of the union of Transylvania with Romania after World War I in 1918. The proportion of Hungarians in Transylvania was in steep decline as more of the region's inhabitants moved into urban areas, where the pressure to assimilate and Romanianize was greater. The expropriation of the estates of Magyar magnates, the distribution of the lands to the Romanian peasants, and the policy of cultural Romanianization that followed the Treaty of Trianon were major causes of friction between Hungary and Romania. Other factors include the emigration of non-Romanian peoples, assimilation and internal migration within Romania (estimates show that between 1945 and 1977, some 630,000 people moved from the Old Kingdom to Transylvania, and 280,000 from Transylvania to the Old Kingdom, most notably to Bucharest). Current population According to the results of the 2011 Population Census, the total population of Transylvania was 6,789,250 inhabitants and the ethnic groups were: Romanians – 70.62%, Hungarians – 17.92%, Roma – 3.99%, Ukrainians – 0.63%, Germans – 0.49%, other – 0.77%. Some 378,298 inhabitants (5.58%) have not declared their ethnicity. The ethnic Hungarian population of Transylvania form a majority in the counties of Covasna (73.6%) and Harghita (84.8%). The Hungarians are also numerous in the following counties: Mureș (37.8%), Satu Mare (34.5%), Bihor (25.2%), and Sălaj (23.2%). Economy Transylvania is rich in mineral resources, notably lignite,