The slopes are also positioned facing the south or south-west to angle towards the sun. The vineyards are extremely small compared to new world vineyards and wine making is dominated by caft rather than industry wines. This makes the lists of wines produced long and complex, and many wines hard to obtain as production is so limited. The wine regions in Germany usually referred to are the 13 defined regions for quality wine. The German wine industry has organised itself around these regions and their division into districts. However, there are also a number of regions for the insignificant table wine ("Tafelwein") and country wine ("Landwein") categories. Those regions with a few exceptions overlap with the quality wine regions. To make a clear distinction between the quality levels, the regions and subregions for different quality level have different names on purpose, even when they are allowed to be produced in the same geographical area. There are 13 defined regions ("Anbaugebiete") in Germany:   These 13 regions ("Anbaugebiete") are broken down into 39 districts ("Bereiche") which are further broken down into collective vineyard sites ("Großlagen") of which there are 167. The individual vineyard sites ("Einzellagen") number 2,658. Data from 2016. There are seven regions for Tafelwein ("Weinbaugebiete für Tafelwein"), three of which are divided into two or three subregions ("Untergebiete") each, and 21 regions for Landwein ("Landweingebiete"). These regions have the following relationship to each other, and to the quality wine regions:  Overall nearly 135 grape varieties may be cultivated in Germany – 100 are released for white wine production and 35 for red wine production. According to the international image, Germany is still considered a region for white wine production. Since the 1980s, demand for German red wine has constantly increased, and this has resulted in a doubling of the vineyards used for red wine. Nowadays, over 35% of the vineyards are cultivated with red grapes. Some of the red grapes are also used to produce rosé. Out of all the grape varieties listed below, only 20 have a significant market share. During the last century several changes have taken place with respect to the most planted varieties. Until the early 20th century, Elbling was Germany's most planted variety, after which it was eclipsed by Silvaner during the middle of the 20th century.