How Trends data is adjusted
Trends adjusts search data to make comparisons between terms easier.
Search results are proportionate to the time and location of a query:
Each data point is divided by the total searches of the geography and time range it represents, to compare relative popularity. Otherwise places with the most search volume would always be ranked highest.
The resulting numbers are then scaled on a range of 0 to 100 based on a topic’s proportion to all searches on all topics.
Different regions that show the same number of searches for a term will not always have the same total search volumes.