The graphs above show the relative frequency that the term "world heritage" is used as a search term in Google (top) and the frequency the term appears in news items indexed by Google (bottom). (Click here for explanations of the scales used.) It was obtained using Google Trends.
There seem to be some clear trends. The number of searches on the term has gone down from year to year, and there was much more variability in the number of searches within years in the early years. The number of searches within years tends to be a minimum in the final week of the year.
The volume of indexed literature containing the term has increased from year to year. There is a peak in World Heritage references in the middle of the year which seems to correspond to the annual meeting of the World Heritage Committee. The Committee usually meets in July and makes decisions as to the new sites to include in the World Heritage List and those to add to the List in Danger. Thus it is not surprising that the World Heritage Center generates news stories at that time.
If you go to the site, you can see trends for the last 30 days, for the last 12 months, or for any of the eight years for which there are data. Graphs for shorter periods give more detail as to the key news stories that generate especially high numbers of searches. Additional information is available as to the locations and languages which generate the searches.
While this data is interesting per se, the brief experiment for which results are described above illustrates that a great deal of information can be obtained rather quickly using computer search techniques and the huge amount of data now available on the Internet.