To animate chart data series or category individually, click on the slide to deactivate your chart. Then select the chart (single click) and choose Custom Animation from the Slide Show menu. Add your animation and look for a “group” option.
What kind of “group” (by series, by category, etc.) is available depends on a combination of the chart type and specific animation you’ve selected.
Usually a simple Wipe animation can be applied to both series and category groups.
If you only see “all at once” in your group dropdown, then see if choosing a different animation or changing the chart type gives you more options.
Additional info from http://tinyurl.com/8zovj:
So let’s start with creating a column chart that has one series as a line. (Pedantic instructions for those who may be following the discussion.)
Insert/New Slide. Scroll to the bottom of the slide layout pane and select the Title and Chart slide layout. Now double-click where it says to on the slide. You get a 3D chart with dummy data.
Right-click above the legend and select Chart Type. Choose the first chart subtype — the 2D clustered column. Click OK.
Now right-click the middle data series (the blue columns) and select Chart Type again. Choose Line and click OK.
Now you have two columns and a line.
To animate this chart, you select the chart on the slide, right-click and choose Custom Animation to turn on the animation task pane. In the Custom Animation task pane, choose Add Effect and then select an effect. I suggest that you choose Wipe for this exercise.
In the task pane, you’ll see the chart listed (it probably says Chart 2). Double-click that. (Or click the arrow to the right and choose Effect Options.) On the Chart Animation tab, click the arrow next to “as one object” in the “Group Chart” area. Choose “by series.” Deselect the “animate grid and legend” option and click OK.
Make sure AutoPreview is selected at the bottom of the taskpane and then click the Play button to see a preview of the animation. The two columns will wipe up from the bottom, and the line will do the same. But it will actually look like it just appears because, of course, there’s not much vertical area on a horizontal line, so the wipe doesn’t look like a wipe.
To fix this, we’ll change the wipe direction on the line. Click the downward-pointing chevron just below the chart in the taskpane to expand the chart animation. (This link shows this for a text animation. It may help you see what’s going on here.) Click on the last series in the list (Chart 2, Series 3 here) and then above that where it says Start: Direction: Speed:, change Direction to From Left. Change Speed to Medium.
Click the Play button at the bottom of the taskpane. If the animation looks pretty much like you want it to, then hit Shift+F5 to view it in slide show view. Remember that your animation is set to play on mouseclick, so you’ll have to click to make each column and the lines animate in.
Oh, duh. Instead of Shift+F5, you can just hit the Slide Show button at the bottom of the animation taskpane.
Hopefully that will get you going. The key is to choose animations that allow you to animate “by series” or “by column” or “by element” in the Chart Animation tab.
Note that if you’ve used a true trendline (right-click a data series and choose Add Trendline), the trendline is tied to the data series. It’s not considered its own series. You’d have to animate that type of chart using “by element in series,” expand the list of animations, and change each of the trendline segments to “from left.” You could also drag (or use the Re-Order buttons at the bottom of the taskpane) the trendline segments together and change them to “after previous” instead of “on mouse click” so they come in together as one line.