|| Double-counting: In Myanmar and other countries in which we compile our national figures from multiple sources, some IDPs may have been counted more than once. We reduce this risk by taking into account the geographical and temporal scope our sources’ data. || Partners change their data collection methodology, as in Ethiopia, or the scope of their geographical coverage, as in Nigeria or Burundi. || We change our primary source because of the lack of available data or doubts about their credibility, meaning we are working with two very different data sets from one year to the next. || There is a lack of data on a flow that significantly affects the number of IDPs in a country. Data on the number of refugees and asylum seekers from Syria does not indicate whether they had previously been displaced internally. Similarly, there are indications of displacements in south-eastern Chad as a result of the crisis in the Central African Republic (CAR), but a lack of reliable, updated and verified data. || Delays in data collection after events leading to displacement toward the end of the year often make it impossible to disaggregate flows by year. In several countries, the yearend figures for 2016 only became available in February or March 2017. Reflecting the date of sources When situations remain unchanged from one year to the next, or when flow data is not available, we base our end-of-year estimates on the data provided by our partners. In many countries, however, it has not been updated for several years. In those with complex or multiple displacement crises, such as Chad, Iraq and Myanmar, data for one crisis may be regularly reported, while for others it may be outdated or missing. If there is no credible evidence that IDPs in such situations have returned, integrated locally or settled elsewhere, we have in the past included them in our global figures. In the interests of transparency, this year’s report stratifies the stock of IDPs based on when the primary data was collected (see figure A.4). The length of the bar as a whole represents the total number of IDPs for whom we were able to obtain data. The right-hand section represents data which is increasingly out of date. Accounting for displacement associated with disasters Our estimates for displacement associated with disasters are generated by event rather than by country. We monitor and collect information for all reported disasters from partners including governments, the UN, IFRC and national Red Cross and Red Crescent societies, NGOs and international media outlets. We apply no threshold when doing so, either in terms of the number of people displaced or the distance they have travelled. Our database includes records of one up to 15 million IDPs. We generate a single “new displacement” estimate for the total number of people displaced by each event. It is important to note that this figure is not necessarily the same as the peak number of IDPs, but instead aims to provide the most comprehensive cumulative figure for those displaced with minimal double-counting. Figure A.4: Different strata for conflict related stocks of IDPs, ordered by the date of the source data Source: IDMC 100 GRID 2017