Don't understand my data usage for this month (TelkomInternet)

[Threepwood]

My TiTracker shows the following for data usage this December on the TI report option:

Blended
Downloaded : 3.0555 GB
Uploaded : 76.3893 MB
Total Bandwidth used : 3.1301 GB
Total Usage for December : 2.0981 GB

My total bandwidth used is 3gb, but my total usage for december is 2gb.

Can anyone explain please?

 

[Threepwood]

Just checking on previous months it looks like the smaller number just hasn't had the extra cap added to it yet, previous months totals add up more or less.