2 June 1997

1 July 1997

7.2p

6.0p

5.2p

8 December 1997

13 February 1998

14.2p

11.9p

10.4p

1 June 1998

14 August 1998

7.6p

6.3p

5.5p

7 December 1998

12 February 1999

15.8p

13.2p

11.4p

24 May 1999

13 August 1999

8.8p

7.4p

6.4p

6 December 1999

11 February 2000

18.7p

15.6p

13.6p

10 July 2000

11 August 2000

10.1p

8.4p

7.3p

22 January 2001

23 February 2001

21.6p

18.0p

15.6p

11 July 2001

10 August 2001

10.8p

9.0p

7.8p

23 January 2002

22 February 2002

23.7p

19.8p

17.2p

10 July 2002

9 August 2002

12.0p

10.0p

8.7p

22 January 2003

21 February 2003

23.0p

N/A

20.0p

9 July 2003

8 August 2003

12.0p

N/A

10.4p

21 January 2004

20 February 2004

30.0p

N/A

26.1p

7 July 2004

6 August 2004

15.0p

N/A

13.0p

19 January 2005

18 February 2005

35.0p

N/A

30.4p

6 July 2005

5 August 2005

16.5p

N/A

14.3p

18 January 2006

17 February 2006

39.5p

N/A

34.4p

5 July 2006

4 August 2006

18.5p

N/A

16.1p

17 January 2007

16 February 2007

43.5p

N/A

37.8p

11 July 2007

10 August 2007

21.0p

N/A

18.2p

16 January 2008

15 February 2008

48.5p

N/A

42.2p

4 June 2008

8 August 2008

24.0p

N/A

20.9p

21 January 2009

20 February 2009

42.2p

N/A

N/A

17 June 2009

19 August 2009

21.0p

N/A

N/A

20 January 2010

19 February 2010

52.0p

N/A

N/A

21 July 2010

20 August 2010

24.3p

N/A

N/A

19 January 2011

18 February 2011

60.0p

N/A

N/A

20 July 2011

19 August 2011

28.1p

N/A

N/A

18 January 2012

17 February 2012

67.0p

N/A

N/A

18 July 2012

17 August 2012

31.7p

N/A

N/A

16 January 2013

18 February 2013

73.9p

N/A

N/A

17 July 2013

16 August 2013

35.2p

N/A

N/A

15 January 2014

17 February 2014

81.2p

N/A

N/A

16 July 2014

19 August 2014

38.8p

N/A

N/A

15 January 2015

15 February 2015

89.3p

N/A

N/A

28 May 2015

30 June 2015

21.4p

N/A

N/A

27 August 2015

30 September 2015

21.4p

N/A

N/A

19 November 2015

31 December 2015

49.1p

N/A

N/A

4 February 2016

31 March 2016

49.1p

N/A

N/A

19 May 2016

30 June 2016

23.5p

N/A

N/A

18 August 2016

30 September 2016

23.5p

N/A

N/A

17 November 2016

30 December 2016 

54.1p 

N/A 

N/A 

16 February 2017

31 March 2017

54.1p

N/A

N/A

18 May 2017

30 June 2017

25.85p

N/A

N/A

17 August 2017

29 September 2017

25.85p

N/A

N/A

16 November 2017

29 December 2017

59.51p

N/A

N/A

22 February 2018

29 March 2018

59.51p

N/A

N/A

24 May 2018

29 June 2018

28.435p

N/A

N/A

23 August 2018

28 September 2018

28.435p

N/A

N/A

22 November 2018

31 December 2018

65.46p

N/A

N/A

21 February 2019

29 March 2019

65.46p

N/A

N/A

23 May 2019

28 June 2019

31.28p

N/A

N/A

22 August 2019

30 September 2019

31.28p

N/A

N/A

21 November 2019

31 December 2019

72.0p

N/A

N/A

20 February 2020

31 March 2020

72.01p

N/A

N/A

28 May 2020

30 June 2020

20.85p

N/A

N/A

20 August 2020

30 September 2020

20.85p

N/A

N/A

26 November 2020

31 December 2020

48.0p

N/A

N/A

18 February 2021

31 March 2021

48.01p

N/A

N/A

27 May 2021

30 June 2021

21.06p

N/A

N/A

19 August 2021

30 September 2021

21.06p

N/A

N/A

25 November 2021

31 December 2021

48.48p

N/A

N/A

17 February 2022

31 March 2022

48.48p

N/A

N/A

26 May 2022

30 June 2022

21.27p

N/A

N/A