Adding calculated Total Line to Chart

Hi All,

I have a Column Graph for which I want to add a Total Line. I have following 3 tables.

Table 1: Asset

Fields: Asset ID, Location City

Table 2: Users

Fields: User ID, Location City

Table 3: Region

Fields: Location City, Region.

Here, Regions are like Asia, Europe, North America, South America etc. Multiple Location City could be under one region for ex: under Asia, it could be Tokyo, Manila, Delhi etc.

I am trying to portray difference between No. of Assets and No. of Users in a Region and multiple by a Potential Cost of an asset for ex: 50 USD.

So, if Asia Region has 150 Asset and 100 Users then Additonal Cost for Asia will be 150-100 = 50 mutiplied by 50 USD = 2500 USD.

But if a region has less no. of Assets than users, Additional cost be zero. i.e. if Europe has 200 Assets and 225 Users then Additional Cost will be zero.

I have created a Measure in Table 1 'Asset' like:

 With this Measure, I have created a column Chart with X-Axis as 'Region' from Table 3 and Y-Axis is Measure "Additional Cost" from Table 1. Table 1 'Asset' and Table 2 'Users' are connected to Table 3 'Regions' via field Location City. 

I want to add one more line in my Column Chart as "Total Addition Cost" which will be sum of all Additional Cost for Regions whereever No. of Assets is mroe than No. of Users i.e. Positive Additional Cost.

How can I do this? Please guide me.