Difference between previous week and this week data

Hi BILASolution and Ashish_Mathur

I cannot share the exact data.

But I would give you an idea hat I am trying to acheive

Table : Sample

Columns : PrincipalBalance (It is amount 1000, 24000, 32448, 767778) , Date (It contains everyday dates), Number(it has values negative, positive i.e 0.76, 0.4,-8.6, 75.0, 23, 5.4, 4.3 .... ), ID

I have created calculated column :

Day Of week = FORMAT ( Sample[Date], "dddd" ) - To extract the week day names from Date column

Date Select = if(Sample[Date] = "Wednesday",Sample[Date],Blank())  - I need the sum(PrincipalBalance) every wednesday for entire week starting Thursday to Wednesday. i.e 10/25/2017 - Wednesday sum(balance) from 10/19/2017 - 10/25/2017.

I have created measures:

Current = CALCULATE(COUNT(Sample[lD]),FILTER(Sample,Sample[Number]< 1))

1-2 Weeks = CALCULATE(COUNT(Sample[lD]),FILTER(Sample,Sample[Number] < 3))

3-4 Weeks = CALCULATE(COUNT(Sample[lD]),FILTER(Sample,Sample[Number] < 5))

5+ Weeks = CALCULATE(COUNT(Sample[lD]),FILTER(Sample,Sample[Number] >= 5))

Sum = Current + 1-2 Weeks + 3-4 Weeks +( 5+ Weeks)

Data Display

Matrix

Rows: Date Select

Column: Months(Date)

Values: Sum

Now I need the difference between 25th Oct and 18th Oct, 18th Oct and 11th Oct and so on...

Number        Balance       Date

0.00              1000            10/24/2017
0.00               2000            10/16/2017
1.00     7000                      10/10/2017
0.00      1000                      10/27/2017
0.00       2000                      10/17/2017
1.10        5000                      10/24/2017
-6.57        3500                        10/10/2017
17.61        2500                         10/2/2017

I need to acheive this. 

Please Help.

Thanks alot for your time