1999-2007

1999-2008

2009-2013

1999-2013

Coeff.

t

Coeff.

t

Coeff.

t

Coeff.

t

k

−0.064

−4.394

−0.061

−4.561

0.077

8.498

-

-

0.100

9.369

0.098

10.992

-

-

0.042

6.205

-

-

-

-

-

-

0.091

4.750

0.743

25.695

0.746

30.454

0.731

24.544

0.869

40.836

0.986

0.987

0.974

0.998