April 1981

April 1981: 145 companies

2 April 1981 16 companies

3 April 1981 4 companies

4 April 1981 4 companies

6 April 1981 12 companies

7 April 1981 8 companies

8 April 1981 5 companies

9 April 1981 4 companies

10 April 1981 5 companies

11 April 1981 6 companies

13 April 1981 6 companies

14 April 1981 12 companies

15 April 1981 4 companies

16 April 1981 6 companies

17 April 1981 5 companies

18 April 1981 1 companies

20 April 1981 7 companies

21 April 1981 6 companies

22 April 1981 8 companies

23 April 1981 7 companies

28 April 1981 7 companies

29 April 1981 8 companies

30 April 1981 4 companies