- 1973[subject unknown]Independent
- 1974[subject unknown]Independent
- 1975[subject unknown]Independent
- 1976[subject unknown]Independent Investigators
- 1977[subject unknown]Independent
- 1978[subject unknown]Independent
- 1979[subject unknown]Independent
- 1980[subject unknown]Independent
- 1981[subject unknown]Independent
- 1982[subject unknown]Independent
- 1983[subject unknown]Independent
- 1985[subject unknown]Independent
- 1986[subject unknown]Independent
- 1987[subject unknown]Independent
- 1988[subject unknown]Principal Investigators
- 1989[subject unknown]Independent
- 1990[subject unknown]Principal Investigators
- 1991[subject unknown]Principal Investigators
- 1992[subject unknown]Principal Investigators
- 1993[subject unknown]Pricipal Investigators
- 1994[subject unknown]Pricinipal Investigators
- 1995[subject unknown]Pricinipal Investigators
- 1996[subject unknown]Principal Investigators
- 1997[subject unknown]Principal Investigators
- 1998[subject unknown]Principal Investigators
- 1999[subject unknown]Principal Investigators
- 2000[subject unknown]Principal Investigators
- 2001[subject unknown]Principal Investigators