You will be given a definition of a task first, then some input of the task.
This task involves creating questions from a given passage that involve some kind of complex reasoning (including numerical reasoning).
The generated questions must require looking at more than one part of the passage to answer. Try to use a variety of reasoning types in your questions (some of the sample reasoning types are illustrated in the 'positive examples' field) and also have a variety of answer types (spans, numbers, dates). A span is a continuous phrase taken directly from the passage or question. In such questions, the answer spans are recommended to be five words. Questions with answer type "number", are expected to start with "How many". For instance, "How long did an event last?" can be phrased as "How many years did an event last?". To increase diversity, try to create more questions for which the answer will be multiple spans. Please create questions that require AT LEAST 2 arithmetic operations as illustrated in the 'positive examples' field. You are encouraged to try DIFFERENT COMBINATIONS of operations and not just limit to the combinations shown in those examples. The more challenging questions you create, the better it is.

Passage: The main sources for the civil war era are the kings' sagas. Heimskringla, Fagrskinna and Morkinskinna all describe the period up to the year 1177, although the parts of Morkinskinna that are preserved only extend to 1157. These three sagas were written c. 1220-1230, and in using them as historical sources, it has to be remembered that they were thus written a fair amount of time after the events they describe. However, they are likely to have been based on earlier works, in particular the saga Hryggjarstykki, written c. 1150, which is lost to us, but was available to the authors of the three aforementioned sagas. Agrip af Noregs konunga sogum also describes the civil war era, but has only been preserved up to the events of c. 1136. The period 1177 to 1240 is treated in detail in contemporaneous sagas: Sverris saga the Bagler sagas and Hakon Hakonsson's saga . These sagas were written very shortly after the events they describe. However, as they don't overlap, we are given only one version of events , and this version tends to be from the viewpoint of the main character of the saga. From the later part of the period, fragments of documentation start to appear. The oldest Norwegian royal letter which is preserved was made out by Philippus the bagler king. Also, a couple of runic inscriptions written by central figures survive: A rune letter, probably written by King Sverre's son, Sigurd Lavard c. 1200 has been found during excavations in Bergen, and an inscription by Magnus Erlingsson's brother, Sigurd Erlingsson Jarlsson, dated 18 June 1194, has been preserved from a portal of the now dismantled Vinje stave church.
Output:
Aproximately how many decades after the civil wars were the sagas written?