8/1/1978

41.6

8/31/1979

38.7

5/31/1979

34.4

12/20/1991

32.09

6/21/1997

31.87

7/5/2002

27.4

7/4/2002

27.4

5/2/1990

25.68

10/15/2018

22.59

5/29/2016

14.88

5/25/2015

11.72