| Period | Trading Days | |
| Pre-Financial Crisis | January 2, 1997-October 26, 2007 | 2779 |
| Financial Crisis | October 29, 2007-November 20, 2008 | 270 |
| Post-Financial Crisis | November 21, 2008-December 31, 2018 | 2555 |
| Overall Observed Time | January 2, 1997-December 31, 2018 | 5604 |