| Outlook | Effective |
| Stable | 28.04.2020 |
| Foreign Currency LT Debt | Effective |
| BBB | 15.02.2019 |
| BBB- | 19.09.2016 |
| BB+ | 20.03.2015 |
| BB+ | 18.09.2015 |
| BB | 23.11.2012 |
| BB+ | 21.12.2011 |
| BBB *N | 11.11.2011 |
| BBB- | 30.03.2009 |
| BBB | 17.11.2008 |
| BBB+ *N | 15.10.2008 |
| BBB+ | 15.06.2006 |
| A- | 19.12.2000 |
| BBB+ *P | 02.02.2000 |
| BBB | 11.12.1998 |
| BBB- *P | 22.01.1998 |
| BBB- | 28.10.1996 |
| BB+ | 31.01.1996 |
| BB+ *N | 07.02.1995 |
| BB+ | 23.11.1994 |
| BB+ *P | 20.04.1992 |
If *P or *N = rating is likely to move up (Positive) or down (Negative)