Since 1990, December has been mostly up.
| Month | Prob. | Average % | Median % | Stdev |
| All | 59.04 % | 0.75 % | 1.13 % | 6.28 % |
| 1 | 57.14 % | 0.23 % | 1.73 % | 5.92 % |
| 2 | 52.38 % | 0.67 % | 0.14 % | 5.87 % |
| 3 | 42.86 % | 0.56 % | -0.04 % | 4.89 % |
| 4 | 76.19 % | 3.88 % | 3.33 % | 6.68 % |
| 5 | 57.14 % | 0.66 % | 1.38 % | 4.54 % |
| 6 | 52.38 % | 0.04 % | 0.02 % | 4.76 % |
| 7 | 52.38 % | 1.05 % | 0.01 % | 7.23 % |
| 8 | 52.38 % | -2.17 % | 0.35 % | 7.04 % |
| 9 | 38.10 % | -3.20 % | -2.29 % | 7.84 % |
| 10 | 71.43 % | 2.53 % | 2.97 % | 6.84 % |
| 11 | 66.67 % | 2.14 % | 3.45 % | 4.72 % |
| 12 | 85.71 % | 2.89 % | 3.01 % | 5.63 % |
