april 1981

april 1981: 234 companies

1. april 1981 56 companies

2. april 1981 14 companies

3. april 1981 7 companies

4. april 1981 2 companies

6. april 1981 12 companies

7. april 1981 8 companies

8. april 1981 8 companies

9. april 1981 7 companies

10. april 1981 7 companies

12. april 1981 1 companies

13. april 1981 4 companies

14. april 1981 11 companies

15. april 1981 14 companies

17. april 1981 1 companies

18. april 1981 2 companies

20. april 1981 2 companies

21. april 1981 2 companies

22. april 1981 3 companies

23. april 1981 8 companies

24. april 1981 6 companies

25. april 1981 3 companies

26. april 1981 1 companies

27. april 1981 9 companies

28. april 1981 10 companies

29. april 1981 6 companies

30. april 1981 30 companies