Steps to calculate diffrence:
Step 1: Go to grafana and create new dashboard
Step 2: Now click on add visualization and add transformation
Step 3: Now click on reduce field and add Last *(for first not null values) and difference
Step 4: Now click on add another transformation and add partition by values transformation
Step 5: Now set field to field
Step 6: Now select the concatenate fields
Step 7: Now select Organize fields by name and type the original name
Now remove unnecessary fields
Final outcome:-
