Table 5.
Statistical differences of relative birth quartile distributions in former (2002 to 2005) and current (2012 to 2015) youth soccer players.
| Category | Period | n | Q1 [%] | Q2 [%] | Q3 [%] | Q4 [%] | X2 | p | Cramer’s V |
|---|---|---|---|---|---|---|---|---|---|
| Total | 2002 to 2005 | 2530 | 34.5 | 25.5 | 23.6 | 16.5 | 11.49 | 0.009 | 0.05 |
| 2012 to 2015 | 2611 | 38.2 | 26.1 | 21.0 | 14.7 | ||||
| U13 | 2002 to 2005 | 905 | 35.7 | 29.3 | 22.3 | 12.7 | 2.49 | 0.477 | 0.04 |
| 2012 to 2015 | 982 | 37.4 | 26.2 | 22.6 | 13.8 | ||||
| U14 | 2002 to 2005 | 1015 | 32.6 | 26.5 | 23.4 | 17.4 | 5.42 | 0.144 | 0.05 |
| 2012 to 2015 | 932 | 37.6 | 25.3 | 21.4 | 15.8 | ||||
| U15 | 2002 to 2005 | 793 | 36.1 | 25.6 | 20.7 | 17.7 | 8.51 | 0.037 | 0.07 |
| 2012 to 2015 | 907 | 40.8 | 25.9 | 20.3 | 13.0 | ||||
| U16 | 2002 to 2005 | 573 | 40.1 | 25.7 | 20.4 | 13.8 | 0.07 | 0.996 | 0.01 |
| 2012 to 2015 | 777 | 39.5 | 26.1 | 20.6 | 13.8 | ||||
| U17 | 2002 to 2005 | 502 | 37.8 | 22.5 | 24.5 | 15.1 | 4.02 | 0.260 | 0.06 |
| 2012 to 2015 | 523 | 40.2 | 26.0 | 21.2 | 12.6 | ||||
| U18 | 2002 to 2005 | 270 | 34.1 | 22.6 | 26.7 | 16.7 | 3.87 | 0.276 | 0.08 |
| 2012 to 2015 | 327 | 37.6 | 26.3 | 20.5 | 15.6 | ||||
Q = relative age quarter; Q1 = January–March, Q2 = April–June, Q3 = July–September, Q4 = October–December.