Table 7 Multi-level regression analysis for changes in sex difference in swimming speed for finalists in the FINA World Championships 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

−0.051

0.015

−0.375

−3.384

0.001

200 m breaststroke

0.025

0.014

0.209

1.785

0.079

100 m backstroke

0.029

0.012

0.271

2.356

0.021

200 m backstroke

0.006

0.014

0.055

0.460

0.647

100 m butterfly

−0.003

0.021

−0.025

−0.168

0.867

200 m butterfly

0.028

0.012

0.325

2.333

0.024

200 m individual medley

0.035

0.018

0.230

1.978

0.052

400 m individual medley

−0.033

0.017

−0.221

−1.884

0.064