| Time Period | Minimum | 25th Percentile | Median | Average | 75th Percentile | Maximum | Standard Deviation |
|---|---|---|---|---|---|---|---|
| 2004-2008 | 0.47 | 0.81 | 0.91 | 0.93 | 1.03 | 2.00 | 0.19 |
| 2009-2013 | 0.49 | 0.83 | 0.93 | 0.95 | 1.04 | 1.97 | 0.19 |
| 2014-2018 | 0.53 | 0.87 | 0.97 | 0.99 | 1.08 | 1.93 | 0.18 |
| Total | 0.47 | 0.83 | 0.93 | 0.96 | 1.05 | 2.00 | 0.19 |