I have a table of several faults similar to one below;
fault_ID    date_reported    date_closed         fault hours
ab1        8/04/2019 1:36    8/04/2019 3:30       1.9
ab2        12/03/2019 18:48  12/03/2019 20:45     1.9
ab3        19/10/2018 22:00  20/10/2018 9:45      11.8
ab4        20/03/2019 10:07  20/03/2019 13:00     2.9
ab5        30/07/2019 8:37   30/07/2019 16:30     7.9
ab6        15/06/2019 12:58  18/06/2019 19:55     78.9
ab7        8/06/2019 22:30   8/06/2019 23:30      1.0
ab8        16/10/2018 0:45   16/10/2018 1:50      1.1
ab9        23/01/2019 1:44   23/01/2019 7:05      5.3
ab10       22/05/2019 6:19   26/07/2019 23:07     1,576.8
using R, I would like to summarise the fault hours per month to get the output below:
   Month    Total Fault hours 
   Oct-18       1.1 
   Nov-18       11.8 
   Dec-18       0.0 
   Jan-19       0.0
   Feb-19       0.0 
   Mar-19       2.0 
   Apr-19       1.9 
   May-19       210.0 
   Jun-19       78.9 
   Jul-19       7.9
I have tried a few suggestions with lubridate but I only seem to be able to get it to work for one fault_ID at a time.. I'm new to R. Thanks in advance for your help.
 
    