Hi David, a simple way to do it with basic rectangles would be:
Make a shape layer by drawing a straight line with the pen tool from bottom to top, the length of the 100% bar. Make the stroke the color and width you want it to be (you will now have one rectangle/bar)
Toggle open the shape layer and in Contents highlight Shape1. Add (use the add button next to Contents) Trim Paths.
Duplicate Shape 1 three times
Select each numbered shape and using its Transform property position the bars where you want them (in order ie Shape 1 first, Shape 2 second etc).
With the Shape Layer selected add 4 Slider Controls
Toggle open all the sliders
Toggle open Shape 1 and, in its Trim Paths, ALT click the End setting and pickwhip it to Slider 1
The same with each shape to its own Slider.
At the 1 second mark keyframe each slider to 0, at 3 seconds add keyframes for 100.
Now in your Effects Control Panel you will see the 4 Slider controls. THE TIMELINE MUST BE AT EXACTLY 3 SECONDS (SITTING EXACTLY OVER THE KEYFRAMES). You can now set each slider to the final %. and the bars will go from 0% to whatever is set for each bar.
If not exactly what you are after it may give you a starting point?