(Per cent per annum)

2008

2010

Apr

3.00

2.68

2.38

Jun

4.40

3.72

3.22

May

3.29

2.45

1.85

Jul

5.26

4.73

4.12

Jun

4.37

3.69

3.15

Aug

5.69

5.38

4.86

Jul

7.54

6.04

4.92

Sep

6.00

5.75

5.36

Aug

5.48

4.71

3.84

Oct

7.85

6.94

6.50

Sep

2.95

2.35

1.98

Nov

7.18

6.50

5.95

Oct

2.48

1.13

0.70

Dec

7.05

6.59

6.34

Nov

6.78

4.20

2.66

2011

Dec

5.78

4.59

3.22

Jan

6.79

6.78

6.41

2009

Feb

6.33

6.66

6.35

Jan

4.06

3.10

2.35

Mar

8.03

7.31

6.89

Feb

3.20

2.68

2.12

Apr

7.42

7.48

7.38

Mar

5.22

3.99

3.20

May

6.77

6.68

6.54

Apr

3.77

3.34

2.82

Jun

6.65

6.67

6.40

May

3.64

3.42

2.89

Jul

6.96

6.63

6.39

Jun

3.46

3.29

2.86

Aug

3.58

4.07

3.88

Jul

2.69

2.57

2.43

Sep

4.64

4.35

3.41

Aug

2.98

2.80

2.69

Oct

5.92

4.95

3.83

Sep

2.61

2.66

2.72

Nov

6.74

5.20

4.24

Oct

2.68

2.93

3.20

Dec

8.04

6.64

5.96

Nov

2.25

2.46

2.73

2012

Dec

2.67

2.51

2.83

Jan

8.89

7.81

6.80

2010

Feb

8.94

8.31

7.18

Jan

2.83

2.93

2.84

Mar

10.09

8.55

7.40

Feb

2.18

2.78

2.67

Apr

8.58

7.73

7.05

Mar

3.44

3.28

3.10

May

7.93

7.22

6.35

Apr

3.47

3.43

3.39

Jun

7.48

6.87

5.90

May

3.44

2.88

2.60

Jul

7.93

7.21

6.52

Note : Market-based exchange rate system was introduced from March 1, 1993.