Beginner question - formatting graph axis

I have read several answered questions in the the forums and can't seem to find exactly what I am looking for.  I am fairly new to Power BI so I am still in the learning phase.  I am trying to display a simple stacked bar chart using the following data:

Code         Duration

H0036        20

H0036        17

H2019        15

H0036        45

H2019        30

My data (from an excel spreadsheet) is over 20k rows of similar data.  I was able to create a bar chart (see below) that groups it by the "Code" column and "Duration" column, however it displays the sum of the total number of the duration column per code.  What I need to show on the X axis is the this total number divided by 60 (the duration stands for minutes, so I would like to display this as total hours and not total minutes).  I have tried measures and calculated formulas and I either I'm not understanding the syntax or how this is supposed to work. 

In summary, I basically need to customize the X axis to show this number in total hours.

Any advice would be greatly appreciated.  Thanks!