Sierra Leone is 77 times larger than Yanshi.
Area: 71,740 km2 World Factbook
Population: 5,743,725 (July 2014) World Factbook
Sierra Leone, officially the Republic of Sierra Leone, is a country in West Africa that is bordered by Guinea to the northeast, Liberia to the southeast, and the Atlantic Ocean to the southwest. Sierra Leone is a constitutional republic with a directly elected president and a unicameral legislature. Wikipedia
Area: 933 km2 calculated
Yanshi is a county-level city administered by the prefecture-level city of Luoyang in western Henan province in the People's Republic of China. Yanshi lies on the Luo River. Erlitou, the main site of the eponymous culture, was discovered here in 1959. Wikipedia