| Level of Post and Telecommunications Services | |||||
| Year | Capacity of Long-distance Telephone Exchanges (circuit) |
Capacity of Local Office Telephone Exchanges (10 000 line) |
Capacity of Mobile Telephone Exchanges (10 000 subscribers) |
Length of Long Distance Optical Cable Lines (km) |
Length of Long Distance Microwave Lines (km) |
| 1978 | 1863 | 405.9 | 13958 | ||
| 1980 | 1969 | 443.2 | 13958 | ||
| 1985 | 11522 | 613.4 | 17275 | ||
| 1989 | 103269 | 1034.7 | 3.7 | 1851 | 26338 |
| 1990 | 161370 | 1231.8 | 5.1 | 3334 | 33626 |
| 1991 | 286325 | 1492.2 | 10.5 | 6490 | 39282 |
| 1992 | 521885 | 1915.1 | 45.3 | 14388 | 54418 |
| 1993 | 1206091 | 3040.8 | 156.1 | 38666 | 64368 |
| 1994 | 2416296 | 4926.2 | 371.6 | 73290 | |
| 1995 | 3518781 | 7203.6 | 796.7 | 106882 | 79634 |
| 1996 | 4162009 | 9291.2 | 1536.2 | 130159 | 71503 |
| 1997 | 4368305 | 11269.2 | 2585.7 | 150754 | 65013 |
| 1998 | 4491595 | 13823.7 | 4706.7 | 194100 | 66518 |
| 1999 | 5032026 | 15346.1 | 8136.0 | 239735 | 65228 |
| 2000 | 5635498 | 17825.6 | 13985.6 | 286642 | 121947 |
| 2001 | 7035769 | 25566.3 | 21926.3 | 399082 | 164052 |
| 2002 | 7730133 | 28656.8 | 27400.3 | 487684 | 193636 |
| 2003 | 8617000 | 35400.5 | 33632.4 | 547076 | 216325 |
| a) The capacity of exchanges in this table excludes the capacity of exchanges owned by users. | |||||