| State | ||||||||||
| Adult IDU Clients by Region | ||||||||||
| Source: IDHW Client Information System | ||||||||||
| 1999-2000 | 2000-2001 | 2001-2002 | 2002-2003 | 2003-2004 | 2004-2005 | 2005 | 2006 | 2007 | 2008 | |
| Region 1 | 94 | 88 | 92 | 119 | 160 | 254 | 302 | 315 | ||
| Region 2 | 50 | 49 | 50 | 65 | 114 | 80 | 99 | 138 | ||
| Region 3 | 137 | 131 | 165 | 137 | 193 | 301 | 341 | 381 | ||
| Region 4 | 180 | 160 | 188 | 124 | 114 | 215 | 379 | 502 | ||
| Region 5 | 76 | 94 | 145 | 128 | 131 | 141 | 285 | 252 | ||
| Region 6 | 64 | 69 | 74 | 118 | 157 | 224 | 228 | 207 | ||
| Region 7 | 79 | 79 | 117 | 137 | 109 | 168 | 265 | 293 | ||
| Total | 680 | 670 | 831 | 828 | 978 | 1383 | 1899 | 2088 | ||