In 1990 the administration district of Sawahlunto was expanded from only 779ha to 27,344ha which brought about an increase in population. Based on the results of the Census survey conducted with the residences in 1995, the population in Sawahlunto reflected to have increased to 55,090 people even though the land area of Sawahlunto remained the same unlike how towns would generally expand in proportion to the population growth. Due to its landscape, the expansion of Sawahlunto became a form of federation of small towns and rural settlements. However, based on the Census in 2000 the growth of its people was proven to be temporary, as the population of Sawahlunto appeared to be declining. Based on the same Census, it was stated that the total population was 50,668 people, which translates to a decline of 8% over a span of 5 years. One of the reasons for this was that a portion of the employee housing of the Ombilin Coal Mining Unit (UPO) was shifted out of the town area of Sawahlunto. From this aspect, it can be inferred that Ombilin coal mining has a very strong influence on Sawahlunto.