too much Unaccounted

I"m trying to see which IP is the most busy.

When look at an ip group with port 80 and 443 Most of the destination traffic is unaccounted. Same thing if check directly on the IP report.

Destination     Traffic(Total: 645.76 GB)     % of total traffic
    206.162.145.230     30.59 GB     5%
    206.162.145.241     13.48 GB     2%
    72.14.162.30         367.54 MB     <1%
    173.222.236.218     187.45 MB     <1%
    192.168.20.79         136.67 MB     <1%
    206.162.145.197     108.39 MB     <1%
    206.162.161.44         87.68 MB     <1%
    69.164.39.47         53.89 MB     <1%
    69.164.39.54         50.5 MB     <1%
    69.164.39.48         44.63 MB     <1%
    206.162.145.199     9.16 MB     <1%
    206.162.145.198     4.47 MB     <1%
    50.21.175.102         3.35 MB     <1%
    unaccounted     600.62 GB     93%

I'm able to see more details in the troubleshoot report because raw data are keept on a per hour basis.