Table 3 Parameter estimates and associated standard errors (s.e.) and tests of significance for the models given by Eq. (1) and Eq (2)

Eq. (1)

α ₀

42.897

0.402

106.607

<0.001

α ₁

0.163

0.002

79.901

<0.001

α ₂

12.413

0.474

26.214

<0.001

Eq. (2)

β ₀₀

−32.350

0.445

−72.659

<0.001

β ₁

3.454

0.128

27.020

<0.001

β ₂

39.932

0.689

57.999

<0.001

β ₀₁

0.524

0.007

70.130

<0.001