, In 2010 the country experienced an outbreak of polio that caused more than 457 cases of polio in both children and adults, and resulted in 29 deaths before being brought under control. Several dialects of Persian (Central Asian dialects of Persian) are spoken in Tajikistan and it is its official language (officially referred to as Tajik). Mountain climbing and hiking tours to the Fann and Pamir Mountains, including the 7,000 m peaks in the region, are seasonally organised by local and international alpine agencies.  And in 2012, the presidents of Tajikistan, Afghanistan, and Iran signed an agreement to construct roads and railways as well as oil, gas, and water pipelines to connect the three countries. , Tajikistan artisans created the Dushanbe Tea House, which was presented in 1988 as a gift to the sister city of Boulder, Colorado. It is often played at Nowruz celebrations. This group of people suffers most from poverty in Tajikistan. , The earliest recorded history of the region dates back to about 500BC when much, if not all, of modern Tajikistan was part of the Achaemenid Empire.
Fertility in Tajikistan. Country's Share of World Pop: Total population in the country as a percentage of total World Population as of July 1 of the year indicated. A value below 2.1 will cause the native population to decline, See also: Countries in the world ranked by Life Expectancy.  More than 500,000 residents fled during this time because of persecution, increased poverty and better economic opportunities in the West or in other former Soviet republics. These are the provinces (viloyat) of Sughd and Khatlon, the autonomous province of Gorno-Badakhshan (abbreviated as GBAO), and the Region of Republican Subordination (RRP – Raiony Respublikanskogo Podchineniya in transliteration from Russian or NTJ – Ноҳияҳои тобеи ҷумҳурӣ in Tajik; formerly known as Karotegin Province). Several million native Tajik speakers also live in neighboring Uzbekistan and Russia. The principal segments are in the southern region and connect the capital with the industrial areas of the Hisor and Vakhsh valleys and with Uzbekistan, Turkmenistan, Kazakhstan and Russia. A Population pyramid (also called "Age-Sex Pyramid") is a graphical representation of the age and sex of a population.  Other projects at the development stage include Sangtuda-2 by Iran, Zerafshan by the Chinese company SinoHydro, and the Rogun power plant that, at a projected height of 335 metres (1,099 ft), would supersede the Nurek Dam as highest in the world if it is brought to completion. Yearly Change: For 2019: absolute change in total population (increase or decrease in number of people) over the last year (from July 1, 2018 to June 30 2019). The country is also home to communities of Catholics, Armenian Christians, Protestants, Lutherans, Jehovah's Witnesses, Baptists, Mormons, and Adventists.
In less than a century the Mongol Empire broke up and modern Tajikistan came under the rule of the Chagatai Khanate.