April 1981

April 1981: 360 companies

April 1, 1981 21 companies

April 2, 1981 8 companies

April 3, 1981 27 companies

April 5, 1981 15 companies

April 6, 1981 14 companies

April 7, 1981 20 companies

April 8, 1981 20 companies

April 9, 1981 15 companies

April 12, 1981 11 companies

April 13, 1981 16 companies

April 22, 1981 51 companies

April 23, 1981 43 companies

April 24, 1981 39 companies

April 27, 1981 40 companies

April 28, 1981 5 companies

April 30, 1981 15 companies