april 1981

april 1981: 360 companies

1. april 1981 21 companies

2. april 1981 8 companies

3. april 1981 27 companies

5. april 1981 15 companies

6. april 1981 14 companies

7. april 1981 20 companies

8. april 1981 20 companies

9. april 1981 15 companies

12. april 1981 11 companies

13. april 1981 16 companies

22. april 1981 51 companies

23. april 1981 43 companies

24. april 1981 39 companies

27. april 1981 40 companies

28. april 1981 5 companies

30. april 1981 15 companies