William Kiefer has seen concerts during 12 years.

Year   Concerts Seen  
2022 1 concert
2009 2 concerts
1995 1 concert
1994 1 concert
1991 2 concerts
1986 1 concert
1980 1 concert
1978 2 concerts
1977 1 concert
1976 1 concert
1975 2 concerts
1967 1 concert