| 年度 | デハ8500形 | デハ8600形 | デハ8700形 | デハ8800形 | サハ8900形 | 計 |
| 年度末両数 | 増 | 減 | 年度末両数 | 増 | 減 | 年度末両数 | 増 | 減 | 年度末両数 | 増 | 減 | 年度末両数 | 増 | 減 |
| 1975 | 7 | 7 | | 7 | 7 | | 7 | 7 | | 0 | | | 7 | 7 | | 28 |
| 1976 | 17 | 10 | | 17 | 10 | | 24 | 17 | | 15 | 15 | | 10 | 3 | | 83 |
| 1977 | 26 | 9 | | 26 | 9 | | 32 | 8 | | 19 | 4 | | 16 | 6 | | 119 |
| 1978 | 27 | 1 | | 27 | 1 | | 38 | 6 | | 20 | 1 | | 17 | 1 | | 129 |
| 1979 | 29 | 2 | | 29 | 2 | | 42 | 4 | | 22 | 2 | | 19 | 2 | | 141 |
| 1980 | 30 | 1 | | 30 | 1 | | 49 | 7 | | 40 | 18 | | 40 | 21 | | 189 |
| 1981 | 30 | | | 30 | | | 49 | | | 40 | | | 46 | 6 | | 195 |
| 1982 | 30 | | | 30 | | | 49 | | | 43 | 3 | | 51 | 5 | | 203 |
| 1983 | 30 | | | 30 | | | 61 | 12 | | 63 | 20 | | 59 | 8 | | 243 |
| 1984 | 33 | 3 | | 33 | 3 | | 74 | 13 | | 82 | 19 | | 66 | 7 | | 288 |
| 1985 | 33 | | | 33 | | | 76 | 2 | | 84 | 2 | | 66 | | | 292 |
| 1986 | 36 | 3 | | 36 | 3 | | 90 | 14 | | 94 | 10 | | 72 | 6 | | 328 |
| 1987 | 41 | 5 | | 41 | 5 | | 109 | 19 | | 107 | 13 | | 78 | 6 | | 376 |
| 1988 | 42 | 1 | | 42 | 1 | | 116 | 7 | | 116 | 9 | | 80 | 2 | | 396 |
| 1989 | 42 | | | 42 | | | 117 | 1 | | 117 | 1 | | 80 | | | 398 |
| 1990 | 42 | | | 42 | | | 117 | | | 117 | | | 80 | | | 398 |
| 1991 | 42 | | | 42 | | | 118 | 1 | | 118 | 1 | | 80 | | | 400 |
| 1992 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1993 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1994 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1995 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1996 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1997 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1998 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 1999 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 2000 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 2001 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 2002 | 42 | | | 42 | | | 118 | | | 118 | | | 80 | | | 400 |
| 2003 | 42 | | | 42 | | | 113 | | 5 | 113 | | 5 | 76 | | 4 | 386 |
| 2004 | 42 | | | 42 | | | 113 | | | 113 | | | 76 | | | 386 |
| 2005 | 40 | | 2 | 40 | | 2 | 110 | | 3 | 110 | | 3 | 74 | | 2 | 374 |
| 2006 | 35 | | 5 | 35 | | 5 | 99 | | 11 | 99 | | 11 | 66 | | 8 | 334 |