When presenting scientific or technical data, many people make the big mistake of treating the presentation as the oral form of a scientific or technical journal. That’s why they jam every possible number and footnote onto a single slide thereby making it totally unreadable to the audience.
The way to do it properly is to pick out the essential points of the topic and focus on them one point and one slide at a time. You can include all your footnotes and references in a handout AFTER the presentation. Or you can tell the audience where they can download the information from a website.
Never throw a bunch of numbers up on a slide. Never show a big matrix of rows and columns of numbers in a presentation. If you intend to demonstrate a trend, show a simple graph or bar chart. and the key word is “simple”. You need to do the number crunching for the audience. In other words, do not expect the audience to sit there and figure out a trend from your raw data. They won’t do that. And if they do, they will definitely not be paying attention to you.
Your slide should not be any more complicated than the slide to the left. Any more words or numbers on that slide would make it too busy to read.
Simplicity is the key to any PowerPoint presentation.