| Time Period | Minimum | 25th Percentile | Median | Average | 75th Percentile | Maximum | Standard Deviation |
|---|---|---|---|---|---|---|---|
| 2004-2008 | 0.86 | 1.03 | 1.07 | 1.07 | 1.11 | 1.51 | 0.07 |
| 2009-2013 | 0.78 | 0.91 | 0.94 | 0.94 | 0.97 | 1.26 | 0.06 |
| 2014-2018 | 0.83 | 0.97 | 1.01 | 1.01 | 1.05 | 1.38 | 0.06 |
| Total | 0.78 | 0.95 | 1.00 | 1.01 | 1.06 | 1.51 | 0.08 |