Estimated, forecast, and projected data
A date and a letter – e.g., 2011e (e for estimate, f for forecast, and p for projected) – often appear on axes in data-driven charts. It's important to express the quality of the data being presented. This is a good practice. A problem arises, however, when the chart is reused at a much later date without updating the data. It is inappropriate and negatively affects the credibility of the company/presenter to present data in a chart as estimated/forecast/projected when it should be an actual number at the current point in time, e.g., if you're presenting a chart in August of 2011 but data for 2010 is labeled as estimated (2010e), this is a red flag to your audience. At this point in time, actual numbers should be available for 2010; and, if not, you should explain why they aren't. Remember to always check your data and update numbers where appropriate when reusing charts from previous presentations.