Getting a Percentage score of a single column and put it on a report

[DevSalvo]

Hi, I've been looking high and low to add a single report on a dashboard. 

In my table I have a column Discovery_source that has several string values that repeat themselves, lets say DiscoveryTool_1, DiscoveryTool_2. Etc...

On a dashboard I need to add a single score report that shows the % of records that match only one of those tools.
I know the calculation should go (DiscoveryTool_1 / AllDiscoveryTools) * 100, and I tried Performance Analytics for this following This Tutorial Here but it didn't work for me as I get "Invalid function" in return, it seems to have something to do with the fact that it can only fetch so much and I'm dealing with a little over 3,000,000 records.

At this point I'm only hoping to put that % somewhere so I can paste it on a widget if possible or somehow get it on that dashboard. (The rest of the reports in the dashboard work fine) 

When using a script, doing the same filters and calculations done on the Performance Analytics I do get the right numbers and it doesn't error out. Is there a way to put that script on a widget to be used in a dashboard? 


Apologies for the long text, if you read this much thank you for your time, any advice is appreciated. 

[anubhavritolia]

Can you please example little bit more with some example and expected result so it may be little easy to help.

[DevSalvo]

Sure, I have to pull a report based on a single column in a table., 

Column is Discovery_Source (It's a string) The column has a variety of values (because we have a set of discovery tools that populate that field)  it looks like below:

I need to make a single score report of the number of records that are AppDynamics (for example) 

So I know the calculation should be (# of Appdynamics Records / # Total records) * 100. But I don't know where I can do this.