1999-2007

1999-2008

2009-2013

1999-2013

Coeff.

t

Coeff.

t

Coeff.

t

Coeff.

t

0.149

5.444

0.131

6.344

0.278

11.28

0.162

9.592

0.219

0.254

0.683

0.341