Question: What is the population of the city in India the headquarters of the Northern Railway are located?

full_context: Document 1: New Delhi: Although colloquially Delhi and New Delhi as names are used interchangeably to refer to the jurisdiction of NCT of Delhi, these are two distinct entities, and the latter is a small part of the former.
Document 2: New Delhi: The Delhi Metro is a rapid transit system serving New Delhi, Delhi, Gurgaon, Faridabad, Noida, and Ghaziabad in the National Capital Region of India. Delhi Metro is the world's 12th largest metro system in terms of length. Delhi Metro was India's first modern public transportation system, which had revolutionised travel by providing a fast, reliable, safe, and comfortable means of transport. The network consists of six lines with a total length of 189.63 kilometres (117.83 miles) with 142 stations, of which 35 are underground, five are at-grade, and the remainder are elevated. All stations have escalators, elevators, and tactile tiles to guide the visually impaired from station entrances to trains. It has a combination of elevated, at-grade, and underground lines, and uses both broad gauge and standard gauge rolling stock. Four types of rolling stock are used: Mitsubishi-ROTEM Broad gauge, Bombardier MOVIA, Mitsubishi-ROTEM Standard gauge, and CAF Beasain Standard gauge.
Document 3: Hazrat Nizamuddin railway station: Nizamuddin हज़रत निज़ामुद्दीन Rapid transit, Light rail, Commuter rail & Regional rail station Location New Delhi, Delhi India 28 ° 35 ′ 21 ''N 77 ° 15 ′ 15'' E ﻿ / ﻿ 28.58917 ° N 77.25417 ° E ﻿ / 28.58917; 77.25417 Elevation 206.7 metres (678 ft) Platforms 7 Construction Structure type Standard (on ground station) Parking Yes Other information Status Functioning Station code NZM Zone (s) Northern Railway zone Division (s) Delhi Electrified Yes Traffic Passengers (Daily) 360,000 + Location Nizamuddin Location within Delhi
Document 4: Languages of India: According to Census of India of 2001, India has 122 major languages and 1599 other languages. However, figures from other sources vary, primarily due to differences in definition of the terms ``language ''and`` dialect''. The 2001 Census recorded 30 languages which were spoken by more than a million native speakers and 122 which were spoken by more than 10,000 people. Two contact languages have played an important role in the history of India: Persian and English. Persian was the court language during the Mughal period in India. It reigned as an administrative language for several centuries until the era of British colonisation. English continues to be an important language in India. It is used in higher education and in some areas of the Indian government. Hindi, the most widely spoken language in a large region of India today, serves as the lingua franca across much of North and Central India. However, there have been anti-Hindi agitations in South India, most notably in the states of Tamil Nadu. There is also opposition in non-Hindi belt states towards imposition of Hindi in these areas.
Document 5: List of languages by number of native speakers in India: Hindi is the most widely spoken language in northern parts of India. The Indian census takes the widest possible definition of ``Hindi ''as a broad variety of`` Hindi languages''. According to 2001 Census, 53.6% of Indian population declared that they speak Hindi either as first or second language, in which 41% of them have declared it as their native language or mother tongue. 12.6% Indians declared that they can speak English as a second language.
Document 6: New Delhi metro station: New Delhi is a station on the Yellow Line of the Delhi Metro. It is within walking distance from the Indian Railways New Delhi station. It is on the Ajmeri Gate (Platform Number 16) side of the New Delhi Railway Station.
Document 7: Languages of India: According to the Census of India of 2001, India has 122 major languages and 1599 other languages. However, figures from other sources vary, primarily due to differences in definition of the terms ``language ''and`` dialect''. The 2001 Census recorded 30 languages which were spoken by more than a million native speakers and 122 which were spoken by more than 10,000 people. Two contact languages have played an important role in the history of India: Persian and English. Persian was the court language during the Mughal period in India. It reigned as an administrative language for several centuries until the era of British colonisation. English continues to be an important language in India. It is used in higher education and in some areas of the Indian government. Hindi, the most commonly spoken language in India today, serves as the lingua franca across much of North and Central India. However, there have been anti-Hindi agitations in South India, most notably in the state of Tamil Nadu.
Document 8: Majnu-ka-tilla: The area lies on a stretch of the National Highway 1, which is part of the historic Grand Trunk Road and the Outer Ring Road of Delhi. It is at a walkable distance from ISBT Kashmere Gate. It is approachable through the Kashmeri Gate station of the Delhi Metro, lies on both the Red (Dilshad Garden - Rithala) and Yellow Lines (Samaypur Badli - HUDA City Centre). It is a transfer station between the Red Line on the highest upper level and the Yellow Line on the lowest level. The Vidhan Sabha metro station is 1.5 km away.
Document 9: Odisha: Odia is the official language along with English as center state communication. Odia is spoken as a native language by 82.7% of the population according to 2011 census. Other minority languages of the state are Hindi, Telugu, Santali, Kui, Urdu, Bengali and Ho.
Document 10: New Delhi: New Delhi has a population of 249,998. Hindi and Punjabi are the most widely spoken languages in New Delhi and the lingua franca of the city. English is primarily used as the formal language by business and government institutes. New Delhi has a literacy rate of 89.38% according to 2011 census, which is highest in Delhi.
Document 11: New Delhi: New Delhi is a major junction in the Indian railway network and is the headquarters of the Northern Railway. The five main railway stations are New Delhi railway station, Old Delhi, Nizamuddin Railway Station, Anand Vihar Railway Terminal and Sarai Rohilla. The Delhi Metro, a mass rapid transit system built and operated by Delhi Metro Rail Corporation (DMRC), serves many parts of Delhi and the neighbouring cities Faridabad, Gurgaon, Noida and Ghaziabad. As of August 2011, the metro consists of six operational lines with a total length of 189 km (117 mi) and 146 stations, and several other lines are under construction. It carries millions of passengers every day. In addition to the Delhi Metro, a suburban railway, the Delhi Suburban Railway exists.
Document 12: New Delhi: New Delhi has one of India's largest bus transport systems. Buses are operated by the state-owned Delhi Transport Corporation (DTC), which owns largest fleet of compressed natural gas (CNG)-fueled buses in the world. Personal vehicles especially cars also form a major chunk of vehicles plying on New Delhi roads. New Delhi has the highest number of registered cars compared to any other metropolitan city in India. Taxis and Auto Rickshaws also ply on New Delhi roads in large numbers. New Delhi has one of the highest road density in India.
Document 13: Languages of India: First, second, and third languages by number of speakers in India (2001 Census) Language First language speakers First language speakers as a percentage of total population Second language speakers Third language speakers Total speakers Total speakers as a percentage of total population Hindi 422,048,642 41.03 98,207,180 31,160,696 551,416,518 53.60 English 226,449 0.02 86,125,221 38,993,066 125,344,736 12.18 Bengali 83,369,769 8.10 6,637,222 1,108,088 91,115,079 8.86 Telugu 74,002,856 7.19 9,723,626 1,266,019 84,992,501 8.26 Marathi 71,936,894 6.99 9,546,414 2,701,498 84,184,806 8.18 Tamil 60,793,814 5.91 4,992,253 956,335 66,742,402 6.49 Urdu 51,536,111 5.01 6,535,489 1,007,912 59,079,512 5.74 Kannada 37,924,011 3.69 11,455,287 1,396,428 50,775,726 4.94 Gujarati 46,091,617 4.48 3,476,355 703,989 50,271,961 4.89 Odia 33,017,446 3.21 3,272,151 319,525 36,609,122 3.56 Malayalam 33,066,392 3.21 499,188 195,885 33,761,465 3.28 Sanskrit 14,135 < 0.01 1,234,931 3,742,223 4,991,289 0.49
Document 14: Urban rail transit in India: There are currently 11 operational rapid transit (also called 'metro') systems in ten cities in India. As of November 2017, India has 425 kilometres (264 miles) of operational metro lines and 347 stations. A further 500 + km of lines are under construction. Metro rail lines in India are composed of mainly standard gauge. Projects like the Kolkata Metro and Delhi Metro used broad gauge for their earliest lines but all new projects in India are on standard gauge as rolling stock imported is of standard gauge.
Document 15: Hyderabad: The most commonly used forms of medium distance transport in Hyderabad include government owned services such as light railways and buses, as well as privately operated taxis and auto rickshaws. Bus services operate from the Mahatma Gandhi Bus Station in the city centre and carry over 130 million passengers daily across the entire network.:76 Hyderabad's light rail transportation system, the Multi-Modal Transport System (MMTS), is a three line suburban rail service used by over 160,000 passengers daily. Complementing these government services are minibus routes operated by Setwin (Society for Employment Promotion & Training in Twin Cities). Intercity rail services also operate from Hyderabad; the main, and largest, station is Secunderabad Railway Station, which serves as Indian Railways' South Central Railway zone headquarters and a hub for both buses and MMTS light rail services connecting Secunderabad and Hyderabad. Other major railway stations in Hyderabad are Hyderabad Deccan Station, Kachiguda Railway Station, Begumpet Railway Station, Malkajgiri Railway Station and Lingampally Railway Station. The Hyderabad Metro, a new rapid transit system, is to be added to the existing public transport infrastructure and is scheduled to operate three lines by 2015.
ground_truth: 249,998
sub_queries: What Indian city is the headquarters of the Northern Railway? Answer: New Delhi
What is the population of New Delhi ? Answer: 249,998