Complex sentence: The Roman Catholic Archdiocese of Warmia is an archdiocese of the Latin Rite of the Roman Catholic Church in present Poland, where about 29.4% of its population went to church at least once per week in 2013.
Split into simpler sentences: The Roman Catholic Archdiocese of Warmia is an archdiocese of the Latin Rite of the Roman Catholic Church in Poland. About 29.4% of its population went to church at least once per week in 2013.