Nepal's Census 2011: Brahmin population gone down and Chhetri population gone up

It is interesting to hear the opinion and perspective of people in regard to the population decreased in the certain caste/ethnic group. For example, Hill Brahman population has gone down slightly and Chhetri population has gone up then previous census 2001. I've discussed about this with some of the researchers from Population Studies background from the same caste groups at CREHPA and they said it might be because in Brahman community if Brahman men marry others caste or ethnic group girls then their caste is degrade to Chhetir (Khatry) so this is the reason WHY population of Brahman gone down and population of Chhetri gone up. 

The final population census 2011 report released yesterday stated that: 

The Hill Brahman population has decreased, according to the National Census Report (2012) released by the Central Bureau of Statistics on Monday. The Hill Brahman population is put at 12.2% of the total population of the country, down from 12.7% in the census of 2001. 

The Brahman Samaj has, meanwhile, claimed that this is a result of the attacks from all sides against Brahmans, and voiced suspicious over the census data. 
"We have proof that many missions were activated to show our population low in the census," Om Sharma, general secretary of the Samaj, told Republica. He added that this was the result of conspiracy. 
There are 125 caste/ethnic groups in Nepal, according to the census. Chhetri is the largest caste/ethnic group, accounting for 16.6% (4,398,053) of the total population, followed by Hill Brahmans (12.2%; 3,226,903). Other figures are Magar (7.1%; 1,887,733), Tharu (6.6%; 1,737,470), Tamang (5.8%; 1,539,830), Newar (5.0% ; 1,321,933), Kami (4.8%; 1,258,554), Muslim (4.4%; 1,164,255), Yadav (4.0%; 1,054,458) and Rai (2.3%; 620,004). 
The lowest population is that of the Kusunda, at only 273. 
Similarly, there are 123 languages spoken as mother tongues reported in the census of 2011. The earlier census of 2001 showed only 92 languages. Ethnic activist and sociologist Dr Om Gurung said that this discrepancy is the result of increasing consciousness of people to their languages, culture and identity. 
"Now, social consciousness, sense of identity and interest in their own culture and language is increasing among the people," said Gurung. 
Nepali is spoken as mother tongue by 44.6 percent (11,826,953) of the total population, followed by Maithili (11.7%; 3,092,530), Bhojpuri (6.0%; 1,584,958), Tharu (5.8%; 1,529,875), Tamang (5.1%; 1,353,311), Newari (3.2%; 846,557), Bajjika (3.0%; 793,418), Magar (3.0%; 788,530), Doteli (3.0%; 787,827) and Urdu (2.6%; 691,546). 
Interestingly, the Nepali mother tongue population has decreased from 48.6% (2001) to 44.6% (2011). 
There are 10 types of religion categories reported in the census. Hinduism is followed by 81.3 percent (21,551,492) of the population, with the other figures being Buddhism (9.0%; 2,396,099), Islam (4.4%; 1,162,370), Kirat (3.1%; 807,169), Christianity (1.4%; 375,699), Prakriti (0.5%; 121,982), Bon (13,006), Jainism (3,214), Bahai (1,283) and Sikhism (609).

Source: http://www.myrepublica.com/portal/index.php?action=news_details&news_id=45505

References
1. National Census 2011: Nepal has 26 million plus people accessed from http://www.myrepublica.com/portal/index.php?action=news_details&news_id=45516
2. Experts question census findings accessed from http://www.myrepublica.com/portal/index.php?action=news_details&news_id=45515
3.  New census puts population at 26.49 million accessed from http://www.ekantipur.com/the-kathmandu-post/2012/11/26/top-story/new-census-puts-population-at-26.49m/242128.html