Before the Mongol invasion, Song dynasty reportedly had approximately 120 million citizens; the 1300 census which followed the invasion reported roughly 60 million people.
bᵻfˌoːɹ ðə mˈɔŋɡɑːl ɪnvˈeɪʒən, sˈɔŋ dˈaɪnɐsti ɹᵻpˈoːɹɾᵻdli hæd ɐpɹˈɑːksɪmətli wˈʌnhˈʌndɹɪd twˈɛnti mˈɪliən sˈɪɾɪzənz; ðə wˈʌn θˈaʊzənd θɹˈiːhˈʌndɹɪd sˈɛnsəs wˌɪtʃ fˈɑːloʊd ðɪ ɪnvˈeɪʒən ɹᵻpˈoːɹɾᵻd ɹˈʌfli sˈɪksti mˈɪliən pˈiːpəl.