| YR | Cover_Actual | IR-1977 | Price Index | Cover-CPI | IR-(r1-r0)/r0 | IR-LOG1-LOG0 | Cover-CPI | Cover-Ceiling | |||
| 1977 | $0.30 | $0.30 | $0.30 | $0.30 | |||||||
| 1978 | $0.35 | $0.32 | 7.60% | $0.32 | 16.67% | 6.69% | $0.32 | $0.35 | |||
| 1979 | $0.40 | $0.34 | 11.30% | $0.39 | 14.29% | 5.80% | $0.36 | $0.40 | |||
| 1980 | $0.40 | $0.38 | 13.50% | $0.45 | 0.00% | 0.00% | $0.41 | $0.50 | |||
| 1981 | $0.50 | $0.43 | 10.30% | $0.44 | 25.00% | 9.69% | $0.45 | $0.60 | |||
| 1982 | $0.60 | $0.48 | 6.20% | $0.53 | 20.00% | 7.92% | $0.48 | $0.65 | |||
| 1983 | $0.60 | $0.51 | 3.20% | $0.62 | 0.00% | 0.00% | $0.49 | $0.70 | |||
| 1984 | $0.60 | $0.53 | 4.30% | $0.63 | 0.00% | 0.00% | $0.51 | $0.75 | |||
| 1985 | $0.60 | $0.55 | 3.60% | $0.62 | 0.00% | 0.00% | $0.53 | $0.80 | |||
| 1986 | $0.65 | $0.57 | 1.90% | $0.61 | 8.33% | 3.48% | $0.54 | $0.85 | |||
| 1987 | $0.75 | $0.58 | 3.60% | $0.65 | 15.38% | 6.21% | $0.56 | $0.90 | |||
| 1988 | $0.75 | $0.60 | 4.10% | $0.78 | 0.00% | 0.00% | $0.59 | $0.95 | |||
| 1989 | $1.00 | $0.62 | 4.80% | $0.79 | 33.33% | 12.49% | $0.61 | $1.00 | |||
| 1990 | $1.00 | $0.65 | 5.40% | $1.05 | 0.00% | 0.00% | $0.65 | $1.10 | |||
| 1991 | $1.00 | $0.69 | 4.20% | $1.04 | 0.00% | 0.00% | $0.67 | $1.15 | |||
| 1992 | $1.00 | $0.72 | 3.00% | $1.03 | 0.00% | 0.00% | $0.69 | $1.20 | |||
| 1993 | $1.25 | $0.74 | 3.00% | $1.03 | 25.00% | 9.69% | $0.71 | $1.25 | |||
| 1994 | $1.50 | $0.76 | 2.60% | $1.28 | 20.00% | 7.92% | $0.73 | $1.30 | |||
| 1995 | $1.50 | $0.78 | 2.80% | $1.54 | 0.00% | 0.00% | $0.75 | $1.35 | |||
| 1996 | $1.50 | $0.80 | 3.00% | $1.54 | 0.00% | 0.00% | $0.78 | $1.40 | |||
| 1997 | $1.50 | $0.83 | 2.30% | $1.53 | 0.00% | 0.00% | $0.79 | $1.45 | |||
| 1998 | $1.50 | $0.85 | 1.60% | $1.52 | 0.00% | 0.00% | $0.81 | $1.50 | |||
| 1999 | $1.75 | $0.86 | 2.20% | $1.53 | 16.67% | 6.69% | $0.82 | $1.55 | |||
| 2000 | $1.99 | $0.88 | 3.40% | $1.81 | 13.71% | 5.58% | $0.85 | $1.65 | |||
| 2001 | $2.25 | $0.91 | 2.80% | $2.05 | 13.07% | 5.33% | $0.88 | $1.70 | |||
| 2002 | $2.25 | $0.93 | 1.60% | $2.29 | 0.00% | 0.00% | $0.89 | $1.75 | |||
| 2003 | $2.25 | $0.95 | 2.30% | $2.30 | 0.00% | 0.00% | $0.91 | $1.80 | |||
| 2004 | $2.25 | $0.97 | 2.70% | $2.31 | 0.00% | 0.00% | $0.94 | $1.85 | |||
| 2005 | $2.25 | $1.00 | 3.40% | $2.33 | 0.00% | 0.00% | $0.97 | $1.95 | |||
| 2006 | $2.50 | $1.03 | 3.20% | $2.32 | 11.11% | 4.58% | $1.00 | $2.05 | |||
| 2007 | $2.99 | $1.06 | 2.80% | $2.57 | 19.60% | 7.77% | $1.03 | $2.15 | |||
| 2008 | $2.99 | $1.09 | 5.50% | $3.15 | 0.00% | 0.00% | $1.08 | $2.30 | |||