▁Ch it wan ▁Valley ▁became ▁a ▁major ▁transport ation ▁hub ▁for ▁all ▁of ▁Nep al . ▁Al ong ▁with ▁this ▁major ▁change ▁came ▁a ▁dram atic ▁increase ▁in ▁government ▁services , ▁business ▁expansion , ▁and ▁growing ▁employ ment , ▁especially ▁in ▁the ▁agricult ural ▁industry . ▁The ▁valley ' s ▁population ▁grew ▁rapidly ▁through ▁both ▁in - m igration ▁and ▁natural ▁increase . ▁ ▁V ital ▁statistics ▁ ▁UN ▁estimates ▁▁ ▁Source : ▁ ▁B irth s ▁and ▁death s ▁ ▁Str ucture ▁of ▁the ▁population ▁▁▁ ▁Str ucture ▁of ▁the ▁population ▁( 2 2 . 0 6 . 2 0 1 1 ) ▁( C ensus ) ▁: ▁ ▁Life ▁expect ancy ▁▁ ▁Source : ▁UN ▁World ▁Population ▁Pro spect s ▁ ▁Dem ographic ▁statistics ▁ ▁Nep al ▁Dem ographic ▁and ▁Health ▁Survey ▁▁ ▁Total ▁F ert ility ▁R ate ▁( TF R ) ▁( W anted ▁F ert ility ▁R ate ) ▁and ▁Cru de ▁B irth ▁R ate ▁( C BR ): ▁ ▁The ▁following ▁dem ographic ▁statistics ▁are ▁from ▁the ▁ 2 0 1 1 ▁Nep al ▁Dem ographic ▁and ▁Health ▁Survey ▁( ND HS ). ▁ ▁Med ian ▁birth ▁intervals ▁( Med ian ▁number ▁of ▁months ▁since ▁preceding ▁birth ) ▁Total : ▁ 3 6 . 2 ▁R ural : ▁ 3 5 . 9 ▁Urban : ▁ 4 0 . 3 ▁( 2 0 1 1 ) ▁ ▁Med ian ▁age ▁at ▁first ▁birth ▁Med ian ▁age : ▁ 2 0 . 1 ▁( 2 0 1