Month

Jan.

Feb.

Mar.

Apr.

May

Jun.

Jul.

Aug.

Sep.

Oct.

Nov.

Dec.

$\langle v_{ex}\rangle$

3.42

3.34

3.22

3.50

3.52

3.21

3.37

3.06

2.68

2.66

2.58

3.18

$\langle v_c\rangle$

3.51

3.44

3.32

3.58

3.61

3.31

3.45

3.15

2.76

2.72

2.62

3.23

Relativeerror (%)

2.6

3.0

3.1

2.3

2.5

2.8

2.4

2.9

3.0

2.2

1.5

1.6