| Passive ownership stake (update) | SC 13G/A | 2001-02-13 | - |
| Quarterly report (amended) | 10-Q/A | 2001-02-02 | 2000-03-31 |
| Quarterly report (amended) | 10-Q/A | 2001-02-01 | 2000-06-30 |
| Quarterly report (amended) | 10-Q/A | 2001-02-01 | 2000-09-30 |
| Annual report (amended) | 10-K/A | 2001-02-01 | 1999-12-31 |
| Major company event | 8-K | 2001-01-12 | 2001-01-11 |
| Quarterly report | 10-Q | 2000-10-30 | 2000-09-30 |
| Passive ownership stake (update) | SC 13G/A | 2000-08-11 | - |
| Passive ownership stake (update) | SC 13G/A | 2000-08-11 | - |
| Quarterly report | 10-Q | 2000-08-04 | 2000-06-30 |
| Employee plan annual report | 11-K | 2000-06-27 | 1999-12-31 |
| Quarterly report | 10-Q | 2000-05-08 | 2000-03-31 |
| Proxy statement | DEF 14A | 2000-03-27 | 2000-05-16 |
| Annual report | 10-K | 2000-03-01 | 1999-12-31 |
| Passive ownership stake (update) | SC 13G/A | 2000-02-11 | - |
| Passive ownership stake (update) | SC 13G/A | 2000-02-07 | - |
| Quarterly report | 10-Q | 1999-11-12 | 1999-09-30 |
| Quarterly report | 10-Q | 1999-08-05 | 1999-06-30 |
| Annual report (amended) | 10-K/A | 1999-06-29 | 1998-12-31 |
| Employee plan annual report | 11-K | 1999-06-25 | 1998-12-31 |
| Proxy statement | DEF 14A | 1999-05-14 | 1999-05-18 |
| Quarterly report | 10-Q | 1999-05-11 | 1999-03-31 |
| 10-K405 | - | 1999-03-01 | 1998-12-31 |
| Passive ownership stake (update) | SC 13G/A | 1999-01-08 | - |
| Passive ownership stake | SC 13G | 1999-01-07 | - |
| Quarterly report | 10-Q | 1998-11-05 | 1998-09-30 |
| Quarterly report | 10-Q | 1998-08-10 | 1998-06-30 |
| Employee stock plan | S-8 | 1998-07-07 | - |
| Annual report (amended) | 10-K/A | 1998-07-01 | 1997-12-31 |
| Employee plan annual report | 11-K | 1998-06-26 | 1997-12-31 |
| Quarterly report | 10-Q | 1998-05-08 | 1998-03-31 |
| Passive ownership stake (update) | SC 13G/A | 1998-04-13 | - |
| Proxy statement | DEF 14A | 1998-03-27 | 1998-05-12 |
| 10-K405 | - | 1998-02-26 | 1997-12-31 |
| Passive ownership stake (update) | SC 13G/A | 1998-02-10 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-05 | - |
| Activist ownership stake | SC 13D | 1998-01-20 | - |
| Major company event | 8-K | 1997-11-24 | 1997-11-20 |
| Prospectus supplement | 424B5 | 1997-11-24 | - |
| Prospectus supplement | 424B5 | 1997-11-17 | - |
| Quarterly report | 10-Q | 1997-11-06 | 1997-09-30 |
| Securities registration | S-3 | 1997-10-15 | - |
| Activist ownership stake | SC 13D | 1997-09-05 | - |
| Quarterly report | 10-Q | 1997-07-31 | 1997-06-30 |
| Employee plan annual report | 11-K | 1997-06-27 | 1996-12-31 |
| Quarterly report | 10-Q | 1997-05-01 | 1997-03-31 |
| Proxy statement | DEF 14A | 1997-03-25 | 1997-05-13 |
| PRE 14A | - | 1997-03-14 | 1997-05-13 |
| Major company event | 8-K | 1997-03-04 | 1997-03-03 |
| 8-A12B/A | - | 1997-03-04 | - |
