| Time Period | Minimum | 25th Percentile | Median | Average | 75th Percentile | Maximum | Standard Deviation |
|---|---|---|---|---|---|---|---|
| 2004-2008 | 0.49 | 0.82 | 0.91 | 0.94 | 1.02 | 1.90 | 0.18 |
| 2009-2013 | 0.53 | 0.86 | 0.96 | 0.98 | 1.07 | 1.89 | 0.18 |
| 2014-2018 | 0.53 | 0.86 | 0.96 | 0.97 | 1.06 | 1.88 | 0.18 |
| Total | 0.49 | 0.85 | 0.94 | 0.96 | 1.05 | 1.90 | 0.18 |