| Company | Ranking | Outlook | Date |
|---|---|---|---|
| S&P | BB- | Steady | Mar 08 2023 |
| S&P | BB- | Optimistic | Might 20 2022 |
| Moody’s | Ba2 | Steady | Apr 01 2022 |
| Moody’s | Ba2 | Detrimental | Nov 20 2020 |
| S&P | BB- | Steady | Apr 30 2020 |
| Moody’s | Ba1 | Detrimental | Mar 27 2020 |
| S&P | BB | Detrimental | Nov 22 2019 |
| Moody’s | Baa3 | Detrimental | Nov 01 2019 |
| Moody’s | Baa3 | Steady | Mar 23 2018 |
| S&P | BB | Steady | Nov 24 2017 |
| Moody’s | Baa3 | Underneath Evaluation | Nov 24 2017 |
| Moody’s | Baa3 | Detrimental | Jun 09 2017 |
| Moody’s | Baa2 | Detrimental Watch | Apr 03 2017 |
| S&P | BB+ | Detrimental | Apr 03 2017 |
| Moody’s | Baa2 | Detrimental | Might 06 2016 |
| Moody’s | Baa2 | Detrimental Watch | Mar 08 2016 |
| S&P | BBB- | Detrimental | Dec 04 2015 |
| Moody’s | Baa2 | Steady | Nov 06 2014 |
| Moody’s | Baa2 | Detrimental | Nov 06 2014 |
| S&P | BBB- | Steady | Jun 13 2014 |
| S&P | BBB | Detrimental | Oct 12 2012 |
| Moody’s | Baa1 | Detrimental | Sep 27 2012 |
| S&P | BBB+ | Detrimental | Mar 28 2012 |
| Moody’s | A3 | Detrimental | Nov 09 2011 |
| S&P | BBB+ | Steady | Jan 25 2011 |
| Moody’s | A3 | Steady | Jul 16 2009 |
| S&P | BBB+ | Detrimental | Nov 11 2008 |
| Moody’s | Baa1 | Optimistic | Jun 05 2007 |
| S&P | BBB+ | Steady | Aug 01 2005 |
| Moody’s | Baa1 | Steady | Jan 11 2005 |
| Moody’s | Baa2 | Optimistic Watch | Oct 14 2004 |
| S&P | BBB | Steady | Might 07 2003 |
| Moody’s | Baa2 | Optimistic | Feb 26 2003 |
| S&P | BBB- | Optimistic | Nov 12 2002 |
| Moody’s | Baa2 | Steady | Nov 29 2001 |
| Moody’s | Baa3 | Optimistic Watch | Oct 12 2001 |
| S&P | BBB- | Steady | Feb 25 2000 |
| Moody’s | Baa3 | Optimistic | Feb 07 2000 |
| Moody’s | Baa3 | Steady | Oct 08 1998 |
| Moody’s | Baa3 | Detrimental Watch | Jul 17 1998 |
| S&P | BB+ | Steady | Nov 20 1995 |
| S&P | BB | Steady | Oct 03 1994 |
| Moody’s | Baa3 | Steady | Oct 03 1994 |
