| Employee plan annual report | 11-K | 1998-06-29 | 1997-12-31 |
| Prospectus supplement | 424B2 | 1998-05-26 | - |
| Quarterly report | 10-Q | 1998-05-13 | 1998-03-31 |
| Prospectus supplement | 424B2 | 1998-05-04 | - |
| Prospectus supplement | 424B2 | 1998-05-04 | - |
| Major company event | 8-K | 1998-04-27 | 1998-04-24 |
| Major company event | 8-K | 1998-04-20 | 1998-04-14 |
| Major company event | 8-K | 1998-04-17 | 1998-04-15 |
| Passive ownership stake (update) | SC 13G/A | 1998-04-03 | - |
| Annual report | 10-K | 1998-03-18 | 1997-12-31 |
| PRE 14A | - | 1998-02-27 | 1998-03-13 |
| Passive ownership stake | SC 13G | 1998-02-13 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-12 | - |
| Passive ownership stake (update) | SC 13G/A | 1998-02-04 | - |
| Major company event (amended) | 8-K/A | 1997-12-23 | 1997-10-06 |
| Major company event | 8-K | 1997-12-11 | 1997-12-11 |
| Quarterly report | 10-Q | 1997-11-14 | 1997-09-30 |
| Major company event (amended) | 8-K/A | 1997-10-16 | 1997-10-06 |
| Major company event | 8-K | 1997-10-08 | 1997-10-06 |
| Employee plan annual report | 11-K | 1997-10-01 | 1997-03-31 |
| Employee plan annual report | 11-K | 1997-10-01 | 1997-03-31 |
| Employee stock plan | S-8 | 1997-10-01 | - |
| Employee plan annual report | 11-K | 1997-09-29 | 1997-03-31 |
| Major company event | 8-K | 1997-08-28 | 1997-08-28 |
| Major company event | 8-K | 1997-08-28 | 1997-08-26 |
| Quarterly report | 10-Q | 1997-08-05 | 1997-06-30 |
| Quarterly report | 10-Q | 1997-05-15 | 1997-03-31 |
| Prospectus supplement | 424B2 | 1997-04-30 | - |
| Prospectus supplement | 424B2 | 1997-04-30 | - |
| Major company event | 8-K | 1997-04-22 | 1997-04-17 |
| Employee stock plan | S-8 | 1997-03-27 | - |
| Annual report | 10-K | 1997-03-26 | 1996-12-31 |
| Proxy statement | DEF 14A | 1997-03-12 | 1996-04-19 |
| Passive ownership stake (update) | SC 13G/A | 1997-02-14 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-10 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-04 | - |
| Prospectus supplement | 424B2 | 1997-01-30 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-01-30 | - |
| Major company event | 8-K | 1997-01-27 | 1997-01-24 |
| Prospectus supplement | 424B5 | 1997-01-24 | - |
| Major company event | 8-K | 1997-01-22 | 1997-01-21 |
| Employee stock plan | S-8 | 1996-12-20 | - |
| Quarterly report | 10-Q | 1996-11-08 | 1996-09-30 |
| 8-A12B | - | 1996-10-29 | - |
| Major company event (amended) | 8-K/A | 1996-10-17 | 1996-10-16 |
| Major company event | 8-K | 1996-10-16 | 1996-10-16 |
| Employee plan annual report | 11-K | 1996-09-27 | 1996-03-31 |
| Quarterly report | 10-Q | 1996-08-14 | 1996-06-30 |
| Major company event | 8-K | 1996-07-31 | 1996-07-24 |
| Major company event | 8-K | 1996-07-02 | 1996-07-02 |
