the streets from this era are still extant, and some of those proposed have been realised with some minor modifications. The population grew from less than 10,000 in the early 17th century to more than 50,000 in the mid-1670s. The city's income rose from 18,595 daler in 1635–36 to 81,480 daler in 1644. In 1642, approximately 60 per cent of that sum was spent on construction works. Trade Other Swedish cities were deprived of their export privileges by the so-called "Bothnian Trade Coercion" (Bottniska handelstvånget). Most Swedish cities were granted a trade monopoly over a limited surrounding area, but for Stockholm most of the lands surrounding the Gulf of Bothnia formed part of the city's trade territory. However, the state-granted monopoly was not the only thing that favoured Stockholm at that time. It was one of the best natural harbours of the era and throughout the 17th century, countless foreign visitors marvelled at the sight of large ships "with 60 or 70 cannons" moored along the eastern quay next to the royal castle. In contrast with other Swedish cities, all of which were self-supporting, Stockholm was completely dependent of the transit passing through the city—it had, for example, about the same number of domestic animals as Uppsala, which only had ten per cent the population of the capital. All goods brought into Stockholm had to pass through one of six customs stations, and approximately three-fourths of them were exported from the city. Half of the remaining items, mostly fishery products, were delivered from the Baltic, and corn came from the Lake Mälaren region. However, during the latter half of the century, the rapidly growing capital could not be supported by the Lake Mälaren region alone and therefore became dependent on corn imported from the provinces. Sweden had played a passive role in international trade during the 16th century; German merchants and ships managed the export of Swedish primary products such as osmond iron, raw copper, and butter. This export was largely regarded as a means of securing the import of items not available in Sweden, such as salt, wine, and luxury goods demanded at the court. With the introduction of a mercantile doctrine around 1620, trade became a keystone to governmental income and the Swedish economy subsequently focused on export, not of raw materials, but of refined products. Over the entire period (c. 1590–1685), Stockholm's share of the national economy