DSL Bandwidth Utilization

I am looking in calculating dsl port bandwidth utilization percentage
from raw peg counts recieved from an Element management system.
Question is what is the raw counts I should be using for a general
(common) bandwidth utilization percentage? I do have access to many
raw peg counts. Below is a small set of the ones I think would be
used; is there any others I should look for or need?

atm_in_cell_total - atm in cell total
atm_out_cell_total - atm out cell total
ds_current_data_rate - downstream current data rate (kbps)
us_current_data_rate - upstream current data rate (kbps)

Can someone provide me a generic formula for bandwidth utilization
percentage?

Thanks
Jim