Highest frequencies of day of week in rolling 7 weeks for each ID (with link and examples)

[buyer66]

https://docs.google.com/spreadsheets/d/1g-YB3VdZSiEJ57Q0ewrb7uZ3J6Wi5h0L5KxQkklKKNM/edit?usp=sharing... 

I have a table with 3 columns: ID, WeekID and DayofWeek
Would like to calculate the MaxFrequency column that shows the highest appearance of frequency of a day in rolling 7 weeks.
For example, ID 11 in WeekID 202320 has 2 tie frequencies: 1 and 4, each appears twice, then the value for MaxFrequency will be 2.
In WeekID 202318, rolling 7 weeks shows: 0-1-6-4-4-5-4, so 4 has 3 appearances, then MaxFrequency will be 3.

Don't know how to get it automated with Power Query?

Appreciate your help.

ID	WeekID	DayofWeek	MaxFrequency
11	202320	1	2	1
11	202319	3	2	3	3
11	202318	0	3	0	0	0
11	202317	1	3	1	1	1
11	202316	6	3	6	6	6
11	202315	4	3	4	4	4
11	202314	4	3	4	4	4
11	202313	5	2		5	5
11	202312	4	3			4
11	202311	6
11	202310	3
11	202309	2
11	202308	4
11	202307	3
11	202306	4
11	202305	3
11	202304	0
11	202303	1
11	202302	6
11	202301	0
22	202320	0
22	202319	6
22	202318	0

[buyer66]

Thank you so much. It works perfectly.
However, just realized that I need to account for the ID that has no value in some WeekID. 
So in the example below, MaxFrequency for ID 1102269 will be counted = 1 for Week 202335 (because WeekID 202333, 202332, 202331, 202329 are missing) then only values 5,2,3 of Week 202335, 34, 30 are taken into account.

ID	WeekID	DayofWeek	MaxFrequency
1118815	202336	1	4
1118815	202335	2	4
1118815	202334	1	5
1118815	202333	1	5
1118815	202332	3	4
1118815	202331	2	4
1118815	202330	1	4
1118815	202329	1	3
1118815	202328	1	2
1118815	202327	1	1
1118815	202326	3	1
1102233	202335	4	3
1102233	202334	3	3
1102233	202333	3	3
1102233	202332	3	3
1102233	202331	5	3
1102233	202329	5	2
1102233	202327	5	1
1102269	202335	5	2
1102269	202334	2	2
1102269	202330	3	2
1102269	202328	4	2
1102269	202327	4	1
1102269	202326	5	1
1102359	202335	4	5
1102359	202334	5	6
1102359	202333	5	6
1102359	202332	5	5
1102359	202331	5	4
1102359	202330	3	3
1102359	202329	5	3
1102359	202328	5	2
1102359	202327	5	1
1102359	202326	2	1

[buyer66]

Thanks for your kind help. The script runs well but rows are duplicated.

Could you please help to check? Thank you.

let
Source = GoogleSheets.Contents("https://docs.google.com/spreadsheets/d/1g-YB3VdZSiEJ57Q0ewrb7uZ3J6Wi5h0L5KxQkklKKNM/edit#gid=2033782..."),
Sheet1_Table = Source{[name="Sheet1",ItemKind="Table"]}[Data],
PromoteHeaders = Table.PromoteHeaders(Sheet1_Table, [PromoteAllScalars=true]),
ChangeType = Table.TransformColumnTypes(PromoteHeaders,{{"WeekID", Int64.Type}, {"DayofWeek", Int64.Type}, {"MaxFrequency", Int64.Type}, {"", Int64.Type}, {"_1", Int64.Type}, {"_2", Int64.Type}, {"ID", type text}}),
SelectColumns = Table.SelectColumns(ChangeType,{"ID", "WeekID", "DayofWeek"}),
AddColumn = Table.AddColumn(SelectColumns, "Custom", each Table.Combine(
Table.Group(SelectColumns, "ID",
{"n",each let a=[DayofWeek] in Table.AddColumn(_,"MaxFrequency", Function.ScalarVector(type function(r as any) as any, (m)=>List.Transform(List.Positions(a),(x)=>List.Max(List.Transform(List.Range(a,x,7), each List.Count(List.PositionOf(List.Range(a,x,7),_,2)))))))})[n] ) ),
Expand = Table.ExpandTableColumn(AddColumn, "Custom", {"MaxFrequency"}, {"MaxFrequency"}),
RemoveDuplicates = Table.Distinct(Expand)
in
RemoveDuplicates

[wdx223_Daniel]

let
Source = GoogleSheets.Contents("https://docs.google.com/spreadsheets/d/1g-YB3VdZSiEJ57Q0ewrb7uZ3J6Wi5h0L5KxQkklKKNM/edit#gid=2033782..."),
Sheet1_Table = Source{[name="Sheet1",ItemKind="Table"]}[Data],
PromoteHeaders = Table.PromoteHeaders(Sheet1_Table, [PromoteAllScalars=true]),
ChangeType = Table.TransformColumnTypes(PromoteHeaders,{{"WeekID", Int64.Type}, {"DayofWeek", Int64.Type}, {"MaxFrequency", Int64.Type}, {"", Int64.Type}, {"_1", Int64.Type}, {"_2", Int64.Type}, {"ID", type text}}),
SelectColumns = Table.SelectColumns(ChangeType,{"ID", "WeekID", "DayofWeek"}),
AddColumn = Table.Combine(
Table.Group(SelectColumns, "ID",
{"n",each let a=[DayofWeek] in Table.AddColumn(_,"MaxFrequency", Function.ScalarVector(type function(r as any) as any, (m)=>List.Transform(List.Positions(a),(x)=>List.Max(List.Transform(List.Range(a,x,7), each List.Count(List.PositionOf(List.Range(a,x,7),_,2)))))))})[n]),
in
AddColumn

[wdx223_Daniel]

= Table.Combine(Table.Group(Source,"ID",{"n",each let a=[DayofWeek] in Table.AddColumn(_,"MaxFrequency",Function.ScalarVector(type function(r as any) as any,(m)=>List.Transform(List.Positions(a),(x)=>List.Max(List.Transform(List.Range(a,x,7),each List.Count(List.PositionOf(List.Range(a,x,7),_,2)))))))})[n])