hello Davegent 

i assumed the row 2 result come from the same formula as above.

i am not sure how your visual will be but please check if this accomodate your need.

create three measure for Green, Orange, and Red color calculation in row 2 with following DAX.

Green =
DIVIDE(
    COUNTX(
        FILTER(
            'Table',
            'Table'[Payload Weight]<'Table'[Target Payload]
        ),
        'Table'[Asset ID]
    ),
    COUNTA('Table'[Asset ID])
)

Orange =
DIVIDE(
    COUNTX(
        FILTER(
            'Table',
            'Table'[Payload Weight]<'Table'[Target Plus 10%]
        ),
        'Table'[Asset ID]
    ),
    COUNTA('Table'[Asset ID])
)

Red =
DIVIDE(
    COUNTX(
        FILTER(
            'Table',
            'Table'[Payload Weight]<'Table'[Target Plus 20%]
        ),
        'Table'[Asset ID]
    ),
    COUNTA('Table'[Asset ID])
)

 

 

Hope this will help.

Thank you.