pivot calculated field - using grand total of a field

[smakatura]

I have the following table

Average of APE	Date
nlist	1/1/2018	2/1/2018	3/1/2018	4/1/2018	5/1/2018	6/1/2018	7/1/2018
1208	119	149	121	108	133	106	162
1209	127	136	112	117	128	102	225
1210	114	127	124	106	129	129	179
Grand Total	120	137	119	111	130	112	189

<colgroup><col width="102" style="width: 77pt; mso-width-source: userset; mso-width-alt: 3730;"> <col width="90" style="width: 68pt; mso-width-source: userset; mso-width-alt: 3291;"> <col width="61" style="width: 46pt; mso-width-source: userset; mso-width-alt: 2230;" span="6"> <tbody> </tbody>

these are volume of accounts that are in each of the lists (1208-1210) over the 7 months indicated (1/1/18 - 7/1/18).

so in January individual lists had 119, 127, and 114 list volume respectively. If you average these together you get the 120 that is in the grand total line.


I want to be able to show how far each the values from the grand total (using percentage) for each month.

nlist	1/1/2018	variance off average volume
1208	119	0.01%
1209	127	0.06%
1210	114	0.05%
Grand Total	120	0.04%

<colgroup><col width="68" style="width: 51pt; mso-width-source: userset; mso-width-alt: 2486;" span="2"> <col width="65" style="width: 49pt; mso-width-source: userset; mso-width-alt: 2377;"> <tbody> </tbody>

• I will not know how many lists or months will be induced (so hard referencing the grand total cell will lot help)
• I am ok with using a separate table to show he percentages
• I want this to automatically update so I don't have to do it manually every month

any thoughts? I know calculations inside the pivot table can do lot.