adding end dates

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)

import data from personal server (1900-1983 for now, to be detailed later)