percentages and multiple query columns

In the future, I generally look for data pasted like so:

Return Daternt_dunnNext Pmt #Terms (Months)

Makes it much, much easier to recreate an issue/scenario rather than having to type in all of the data manually.

Here is the Enter Data query I used to recreate your scenario:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("bZBLDsAgCETvwtpEBfz0Fl02Md7/GsVflKYLZvGGiYOlQLRo0XkGA7dMlqEE1RSYxDuRSAoFEXQLPQ1dQ44t9P9BimeQOlJBUh36EjZhhdwIf3OsSNwVvNzJ7VRaZfYz4vH5C7RrBou5WWFaadSp9QU=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type text) meta [Serialized.Text = true]) in type table [#"Return Date" = _t, rnt_dunn = _t, #"Next Pmt #" = _t, #"Terms (Months)" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Return Date", type date}, {"rnt_dunn", type text}, {"Next Pmt #", Int64.Type}, {"Terms (Months)", Int64.Type}})
in
    #"Changed Type"

Here is the first measure, % Renters:

% Renting = CALCULATE(COUNTROWS(Renters),Renters[Return Date]=BLANK(),Renters[rnt_dunn]="P")/COUNTROWS(ALL(Renters))

% Returns

% Returns = CALCULATE(COUNTROWS(Renters),Renters[Return Date]<>BLANK())/COUNTROWS(ALL(Renters))

% Owners

% Owners = CALCULATE(COUNTROWS(Renters),Renters[rnt_dunn]="X")/COUNTROWS(ALL(Renters))

For the next one, create a column:

Payoff = IF([Next Pmt #]<[Terms (Months)],1,0)

And then a Measure:

% Rented Until Owned = CALCULATE(COUNTROWS(Renters),Renters[Payoff]=0,Renters[rnt_dunn]="X")/CALCULATE(COUNTROWS(Renters),Renters[rnt_dunn]="X")

And a Measure:

% Early Payoff = CALCULATE(COUNTROWS(Renters),Renters[Payoff]=1,Renters[rnt_dunn]="X")/CALCULATE(COUNTROWS(Renters),Renters[rnt_dunn]="X")

Should be able to figure out any other calculations that you need from these examples.