I am trying to calculate and display as a graph the average time for each user to complete a task, each user has 3 results.  The data is being imported from a google spreadsheet and recorded in Zoho reports in date format and then converted to mm:ss after formating the column, See below .

However, when attempting create a graph I am unable to get a graph with these results, instead it shows the entire date (dd/mm/YYYY HH:mm:ss. 

I have also attempted to convert the colon (:) to a decimal (.)  and save the Timer column as a number however, the graph reads the entries as a whole number rater than in minutes.  See below  

Any help would be appreciated 

Thanks in advance

Ian