Table 12 Multi-level regression analysis for changes in sex difference in swimming speed for the Olympic champions in freestyle, breaststroke, backstroke, butterfly and individual medley with correction for multiple participations

50 m freestyle

0.005

0.048

0.056

0.112

0.916

100 m freestyle

0.016

0.020

0.362

0.777

0.481

200 m freestyle

0.023

0.063

0.181

0.367

0.732

400 m freestyle

0.007

0.052

0.071

0.142

0.894

800 m freestyle

−0.090

0.045

−0.705

−1.988

0.118

100 m breaststroke

0.023

0.029

0.368

0.792

0.473

200 m breaststroke

−0.081

0.047

−0.652

−1.719

0.161

100 m backstroke

−0.034

0.021

−0.627

−1.608

0.183

200 m backstroke

0.118

0.081

0.586

1.447

0.221

100 m butterfly

−0.013

0.100

−0.065

−0.129

0.903

200 m butterfly

0.004

0.037

0.060

0.120

0.911

200 m individual medley

0.102

0.053

0.693

1.923

0.127

400 m individual medley

0.050

0.040

0.535

1.266

0.274