Table 2 Distributions of birth dates by groups. Group Birth Months (Year of Birth) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec χ2 Elite 1 147 140 112 78 72 83 51 38 37 37 23 16 309.57 ** (2005-2006) 399 233 126 76 293.78 ** Elite 2 486 376 342 273 261 211 213 163 132 124 108 79 719.06 ** (2008-2009) 1024 745 508 311 641.57 ** Amateurs 70 60 57 51 60 44 39 55 59 35 30 31 38.42 (2006-2007) 187 155 153 96 29.09 ** ** p < 0.001