1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | |
East | 5.22 | 5.01 | 5.51 | 6.34 | 6.79 | 7.25 | 7.81 | 8.37 | 8.85 |
West | 3.01 | 3.21 | 3.15 | 3.23 | 3.51 | 3.99 | 4.55 | 5.12 | 5.47 |
Mid | 4.27 | 3.93 | 3.99 | 4.03 | 4.44 | 4.95 | 5.66 | 6.33 | 6.68 |
East/West | 1.74 | 1.56 | 1.75 | 1.96 | 1.94 | 1.81 | 1.72 | 1.63 | 1.62 |
East/Mid | 1.22 | 1.27 | 1.38 | 1.57 | 1.53 | 1.46 | 1.38 | 1.32 | 1.33 |
Mid/West | 1.42 | 1.23 | 1.26 | 1.25 | 1.27 | 1.24 | 1.24 | 1.24 | 1.22 |