Census yrs. | Mountains | Hill | Mountain and Hill | Terai | Total |
1971 | 1,138,610 (9.9) | 6,071,407 (52.5) | 7,210,017 (62.4) | 4,345,966 (37.6) | 11,555,983 |
1981 | 1,302,896 (8.7) | 7,163,115 (45.5) | 8,466,011 (56.4) | 6,556,828 (43.6) | 15,022,839 |
1991 | 1,443,130 (7.8) | 8,419,889 (45.5) | 9,863,019 (53.3) | 8,628,078 (46.7) | 18,491,097 |
2001 | 1,687,859 (7.3) | 10,251,111 (44.3) | 11,938,970 (51.6) | 11,212,453 (48.4) | 23,151,423 |
2011 | 1,781,792 | 11,394,007 | 13,175,799 | 13,318,705 | 26,494,504 |
| (6.7) | (43.0) | (49.7) | (50.3) |
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