| Year | Number of Hospitals |
|---|---|
| 1988 | 1,247 |
| 1989 | 1,658 |
| 1990 | 6,620 |
| 1991 | 1,604 |
| 1992 | 1,591 |
| 1993 | 2,168 |
| 1994 | 2,135 |
| 1995 | 2,284 |
| 1996 | 2,268 |
| 1997 | 2,452 |
| 1998 | 2,438 |
| 1999 | 2,520 |
| 2000 | 3,034 |
| 2001 | 3,377 |
| 2002 | 3,570 |
| 2003 | 3,763 |
| 2004 | 3,305 |
| 2005 | 3,860 |
| 2006 | 3,958 |
| 2007 | 3,998 |
| 2008 | 4,310 |
| 2009 | 4,390 |