Creating a Separate Allocation Table to Compare Usage / Booked Number Against

Hi all,

First post here after recently starting to learn and use Power BI. Really enjoying it so far but still so much to learn and every time you learn something new, it seems to open up about another 100 things that you need to look at!  😂

Anyway, I work in shipping and am trying to create a report where I can compare actual usage of booked containers compared to an allocation of containers by contract number and / or shipping line (carrier).

I have my booking data (which I cannot share) which gives me information such as shipper, port, contract number booked against, number of 20' and number of 40' containers.  There is a line for each individual booking. 

I want to create an allocation table that shows the number of containers we are allocated by shipping line and carrier, example below, this is dummy data but just to give an idea :

What I want to be able to do is create a table and visuals that shows the number of 20' or 40' that have been booked against each carrier and contract number, the 20' and 40' Allocation, then the Difference and the % Used or Remaining.  I have got as far as the below but my 20' column is adding up all of the booked 20' containers instead of just showing the individual numbers for that Contract or Carrier.  

Does that make sense?  I may be going about it the wrong way and may not have explained it properly so please let me know if you need any more info.