| Passive ownership stake | SC 13G | 1999-02-10 | - |
| Passive ownership stake | SC 13G | 1999-02-09 | - |
| Quarterly report (amended) | 10-Q/A | 1998-11-19 | 1998-10-03 |
| Quarterly report | 10-Q | 1998-11-16 | 1998-10-03 |
| Passive ownership stake | SC 13G | 1998-11-10 | - |
| Major company event | 8-K | 1998-11-06 | 1998-10-28 |
| 424B3 | - | 1998-09-22 | - |
| S-4/A | - | 1998-09-18 | - |
| S-4/A | - | 1998-09-16 | - |
| S-4/A | - | 1998-09-15 | - |
| Employee stock plan | S-8 | 1998-09-08 | - |
| S-4/A | - | 1998-09-04 | - |
| S-4/A | - | 1998-09-04 | - |
| Quarterly report | 10-Q | 1998-08-14 | 1998-07-04 |
| S-4 | - | 1998-07-30 | - |
| Employee stock plan | S-8 | 1998-07-23 | - |
| Employee plan annual report | 11-K | 1998-07-10 | 1997-12-31 |
| NT 11-K | - | 1998-06-29 | 1997-12-31 |
| Quarterly report | 10-Q | 1998-05-15 | 1998-04-04 |
| Annual report | 10-K | 1998-03-26 | 1997-12-31 |
| Proxy statement | DEF 14A | 1998-03-26 | 1998-05-05 |
| Passive ownership stake (update) | SC 13G/A | 1998-03-23 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-17 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-17 | - |
| Passive ownership stake | SC 13G | 1998-02-17 | - |
| Passive ownership stake | SC 13G | 1998-02-17 | - |
| Passive ownership stake | SC 13G | 1998-02-17 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-13 | - |
| Passive ownership stake | SC 13G | 1998-02-10 | - |
| Quarterly report | 10-Q | 1997-11-10 | 1997-09-27 |
| 424B4 | - | 1997-09-05 | - |
| Securities registration | S-3 | 1997-08-11 | - |
| Quarterly report (amended) | 10-Q/A | 1997-08-11 | 1997-06-28 |
| Quarterly report | 10-Q | 1997-08-08 | 1997-06-28 |
| Employee plan annual report | 11-K | 1997-07-01 | 1996-12-31 |
| Quarterly report | 10-Q | 1997-06-13 | 1997-03-29 |
| Proxy statement | DEF 14A | 1997-04-28 | 1997-05-20 |
| PRE 14A | - | 1997-04-17 | 1997-05-20 |
| Annual report | 10-K | 1997-03-31 | 1996-12-31 |
| Passive ownership stake (update) | SC 13G/A | 1997-02-20 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-18 | - |
| Passive ownership stake | SC 13G | 1997-02-18 | - |
| Passive ownership stake | SC 13G | 1997-02-13 | - |
| Quarterly report | 10-Q | 1996-11-13 | 1996-08-28 |
| Passive ownership stake | SC 13G | 1996-10-10 | - |
| Quarterly report | 10-Q | 1996-08-14 | 1996-06-29 |
| Passive ownership stake (update) | SC 13G/A | 1996-06-07 | - |
| Quarterly report | 10-Q | 1996-05-14 | 1996-03-30 |
| Passive ownership stake (update) | SC 13G/A | 1996-03-08 | - |
| Passive ownership stake | SC 13G | 1996-03-07 | - |
