| Time Period | Minimum | 25th Percentile | Median | Average | 75th Percentile | Maximum | Standard Deviation |
|---|---|---|---|---|---|---|---|
| 2004-2008 | 0.67 | 0.87 | 0.96 | 0.95 | 1.03 | 1.47 | 0.11 |
| 2009-2013 | 0.63 | 0.86 | 0.98 | 0.96 | 1.05 | 1.60 | 0.13 |
| 2014-2018 | 0.53 | 0.87 | 1.07 | 1.05 | 1.21 | 2.30 | 0.24 |
| Total | 0.53 | 0.87 | 0.99 | 0.99 | 1.08 | 2.30 | 0.18 |