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