from American Libraries
| Year | Number of Titles | Average Price | Price Change | Index |
|---|---|---|---|---|
| 1984 | 272 | 275.23 | — | 100.0 |
| 1985–87 | N/A | N/A | N/A | N/A |
| 1988 | 265 | 338.13 | N/A | 122.9 |
| 1989 | 265 | 354.32 | 4.8% | 128.7 |
| 1990 | 264 | 390.98 | 10.3% | 142.1 |
| 1991 | 264 | 424.68 | 8.6% | 154.3 |
| 1992 | 258 | 467.27 | 10.0% | 169.8 |
| 1993 | 258 | 490.44 | 5.0% | 178.2 |
| 1994 | 258 | 504.86 | 2.9% | 183.4 |
| 1995 | 258 | 542.73 | 7.5% | 197.2 |
| 1996 | 258 | 593.81 | 9.4% | 215.8 |
| 1997 | 257 | 592.84 | -0.2% | 215.4 |
| 1998 | 257 | 611.71 | 3.2% | 222.3 |
| 1999 | 258 | 668.61 | 9.3% | 242.9 |
| 2000 | 261 | 703.56 | 5.2% | 255.6 |
| 2001 | 261 | 786.39 | 11.8% | 285.7 |
| 2002 | 262 | 839.65 | 6.8% | 305.1 |