As of 2003[update], about one-third of the population, or 1.5 million people, lived in 3,500 unregistered squatter-occupied and 2,011 registered slums.[99]: 4 [132]: 92 The authorised slums (with access to basic services like water, latrines, trash removal by the Kolkata Municipal Corporation) can be broadly divided into two groups—bustees, in which slum dwellers have some long term tenancy agreement with the landowners; and udbastu colonies, settlements which had been leased to refugees from present-day Bangladesh by the government.[132][99]: 5 The unauthorised slums (devoid of basic services provided by the municipality) are occupied by squatters who started living on encroached lands—mainly along canals, railway lines and roads.[132]: 92 [99]: 5 According to the 2005 National Family Health Survey, around 14% of the households in Kolkata were poor, while 33% lived in slums, indicating a substantial proportion of households in slum areas were better off economically than the bottom quarter of urban households in terms of wealth status.[3]: 23 Mother Teresa was awarded the Nobel Peace Prize for founding and working with the Missionaries of Charity in Kolkata—an organisation "whose primary task was to love and care for those persons nobody was prepared to look after".[134]