How to Get Column Total

Hi,

I have tried to make sense of numerous existing questions relating to this subject but still cannot get my measure right.

I am attempting to work out "Market Share" in the following table.. Which would be calculated by dividing the "All Delivery Decisions", which is a measure, into the column total of "All Delivery Decision"

The "All Delivery Decisions" measure looks like this:

And an example of the "Early Delivery" measure is this:

Early Delivery =

CALCULATE(

    COUNTA('PowerBI_DeliveryStatistics'[Delivery Decision]),

    'PowerBI_DeliveryStatistics'[Delivery Decision] IN { "Early" }

)

I have managed to build a measure that gives me the total of the "Late Deliveries" but struggling to get the all the deliveries...

Measure = SUMX(ALLSELECTED('PowerBI_DeliveryStatistics'), CALCULATE(COUNT(PowerBI_DeliveryStatistics[LeadTimeDays])))

Can anyone offer some help please?