The template "Population Germany" is used by the infoboxes {{Infobox German location}} and {{Infobox German district}} to retrieve population data for subdivisions of Germany from a central database. The template can also be used outside those infoboxes. The template uses codes for the subdivisions that have been defined by the federal statistics office of Germany (see this link for codes). There is a separate database for each federal state of Germany. The databases are updated regularly, see below.
the population of a city, town or municipality: {{Population Germany|key=15088220}}, result: 33593 (for Merseburg)
the population of a district: {{Population Germany|key=15088}}, result: 183434 (for Saalekreis)
the population of a region (Regierungsbezirk): {{Population Germany|key=053}}, result: 4475530 (for Cologne region)
the population of a state: {{Population Germany|key=15}}, result: 2180684 (for Saxony-Anhalt)
the date for which the population data apply: {{Population Germany|key=15|datref=STAND}}, result: 2020年12月31日 (for Saxony-Anhalt), or {{Population Germany|key=06634005|datref=STAND}}, result: 2020年12月31日 (for Fritzlar, Hesse)
the reference for the population: {{Population Germany|key=15|datref=QUELLE}}, result: Bevölkerung der Gemeinden – Stand: 31. Dezember 2020(PDF). Statistisches Landesamt Sachsen-Anhalt. 2021年6月 (德语). (for Saxony-Anhalt)
Note: the template Population Germany does not accept codes in which the numbers are grouped, e.g. 15 0 88 220. Use the template {{Schlüsselconverter}} for this:
The data are copied from German Wikipedia. This link shows changes to the database templates in German Wikipedia in the last 30 days. If there is a significant change, that hasn't been implemented in English Wikipedia yet (see the table below, and compare with the dates in German Wikipedia), you can update the files at English Wikipedia. Open the German file (e.g. Saarland), and copy the part between the first line with "STAND" in it and the last line with a municipality code in it (in this case "Tholey") to the corresponding part in the English file (in this case {{Metadata Population DE-SL}}). If you don't feel confident editing templates, just leave a note at Template talk:Infobox German location. Several experienced editors watch that talk page.