Is there an expression that uses numeric data to define minimum and maxim values for a bar chart?

[DCMcGee]

I am an IT Analyst for Ralph Lauren but I am developing InfoGraphic presentations on a monthly basis reflecting our world wide IT activities for our corporate office. My immediate difficulty involves creating over a dozen bar graphs that use numeric values instead of percentages.
(1) Is there an expression that would help with this task?
(2) How would I define the minimum and maximum values for each graph?
(3) How would I have animate the bar to the desired position?
(4) How can I use a slider to make this whole process easier?

I would appreciate any suggestions on the most efficiently way to produce (create/update) these reoccuring graphs for our monthly corporate presentations. Each presentations includes 30+ graphs of varying types (pie, bar, x-y/scatter). Each month, the graphs are the same, just diffrent data changes. Once I have a good working model of each type of graph, I could just change the data values - seems simple right?

But alas, this would only work if  all the graphs were calculated using percentage valuse. As I explained earlier After Effects native parameters seem to use only percentage values, yet 27 of the 35 graphs I produce use specific numeric data values. I have viewed dozens of InfoGraphic templates from Envato, but they seem to also calculate their values as percentages not actual number values. Additionally most of the InfoGraphic templates I have seen, seem to only only permit comparing a maximum of 10 different objects nd I need at least 16. 

[Rick Gerard]

The easiest approach is to set up a linear method based on a slider value or the x or y size or position value of another layer or shape layer. If you have a graph that needs a Y axis with values between 40 and 500, and a slider named Value that you can animate between 40 and 500, something like this would give you a Rectangle 1 shape that would change from 10 pixels minimum to 900 pixels high when the slider is moved between 40 and 200. 

x = 100;
t = thisComp.layer("Controls").effect("Value").slider;
y = linear(t, 40, 200, 10, 900);
[x, y]

//AND THIS FOR layer/Contents/Rectangle 1/Tranform Rectangle 1/Anchor Point;
ofst = content("Rectangle 1").content("Rectangle Path 1").size[1] / 2;
[0, ofst]

You will jsut have to put in the ratios you want. I hope this gets you started. 

[DCMcGee]

Fabulous, I used this and it has worked perfectly! Many thanks to you for taking the time to reply.