['un_continent_name[Africa]',
 'un_continent_name[Americas]',
 'un_continent_name[Asia]',
 'un_continent_name[Europe]',
 'un_continent_name[Oceania]',
 'regime[T.Military Dict]',
 'regime[T.Mixed Dem]',
 'regime[T.Monarchy]',
 'regime[T.Parliamentary Dem]',
 'regime[T.Presidential Dem]',
 'start_year']