According to a 2012 Pew demographic study, 55% of the Muslims in Senegal are Sunni of the Maliki madhhab with Sufi influences, whilst 27% are non-denominational Muslim. Islamic communities in Senegal are generally organized around one of several Islamic Sufi orders called tariqas, headed by a ''khalif'' (''xaliifa'' in Wolof, from Arabic ''khalīfa''), who is usually a direct descendant of the group's founder; the study found that 92% of Senegalese Muslims belonged to a Sufi order. The two largest and most prominent Sufi tariqas in Senegal are the Tijaniyya, whose largest Senegalese sub-groups are based in the cities of Tivaouane and Kaolack and has broad following in West Africa outside of Senegal, and the Murīdiyya (Murid), who are based in the city of Touba and has a follower base mostly limited to within Senegal.