tango179:~# vnstat
Database updated: Fri Mar  6 15:28:03 2015

   eth0 since 01/31/15

          rx:  7.38 TiB      tx:  7.30 TiB      total:  14.69 TiB

   monthly
                     rx      |     tx      |    total    |   avg. rate
     ------------------------+-------------+-------------+---------------
       Feb '15      5.35 TiB |    5.31 TiB |   10.66 TiB |   37.84 Mbit/s
       Mar '15      2.03 TiB |    1.99 TiB |    4.03 TiB |   70.96 Mbit/s
     ------------------------+-------------+-------------+---------------
     estimated     11.17 TiB |   10.96 TiB |   22.13 TiB |

   daily
                     rx      |     tx      |    total    |   avg. rate
     ------------------------+-------------+-------------+---------------
     yesterday    358.83 GiB |  350.89 GiB |  709.73 GiB |   68.91 Mbit/s
         today    302.90 GiB |  297.57 GiB |  600.48 GiB |   90.46 Mbit/s
     ------------------------+-------------+-------------+---------------
     estimated    470.02 GiB |  461.75 GiB |  931.77 GiB |