1. American Hospital Association (1991) American Hospital Association Hospital Statistics, 1990–91 Edition, Table 5c, p. 135. American Hospital Association, Chicago, IL.
2. American Hospital Association (1992) American Hospital Association Hospital Statistics, 1991–92 Edition, Table 5c, p. 135. American Hospital Association, Chicago, IL.
3. American Hospital Association (1993) American Hospital Association Hospital Statistics, 1992–93 Edition, Table 5c, p. 135. American Hospital Association, Chicago, IL.
4. American Hospital Association (1994) American Hospital Association Hospital Statistics, 1993–94 Edition, Table 5c, p. 135. American Hospital Association, Chicago, IL.
5. American Hospital Association (1995) American Hospital Association Hospital Statistics, 1994–95 Edition, Table 5c, p. 135. American Hospital Association, Chicago, IL.