| N | Minimum | Maximum | Mean | Std. Dev. | |||||
| SR | 450 | −1.00 | 6.61 | 0.25 | 0.76 | ||||
| DER | 448 | −17.80 | 71.72 | 1.16 | 4.38 | ||||
| LEV | 448 | 0.00 | 11.43 | 0.61 | 1.02 | ||||