What the assignment is suggesting is that you incorporate the data into the written exposition of the essay/report that you are writing. You should state whatever piece of data you are referencing, but you should use complete descriptive sentences to not only report but to connect that data to whatever argument you are proving. You should be describing the significance of the data, not merely stating the data. Presenting data in this way creates a more seamless connection to the analysis or argument of the essay. If you were to present the data in a chart, for example, then the reader of the report has to interpret the data before going on to read whatever you might want to say about it. By incorporating the data into your essay, you are forced to select only the most relevant piece of information and immediately explain it, but it keeps the focus of your essay on target.