Overflow or div by 0 in systat -ifstat?

Hello! Left systat -ifstat running to watch the bandwidth on a few 
Netgraph VPN tunnels overnight, and woke up to this today:

                     /0   /1   /2   /3   /4   /5   /6   /7   /8   /9   /10
      Load Average   |

       Interface           Traffic               Peak                Total
             ng4  in      0.000 Mb/s          0.001 Mb/s            1.976 MB
                  out     0.000 Mb/s          0.000 Mb/s            5.049 MB

             ng3  in      0.000 Mb/s     29132214617622.535 M      46.615 MB
                  out     0.000 Mb/s     29132214589474.320 M       1.143 GB

             ng2  in      0.000 Mb/s          0.384 Mb/s          322.777 MB
                  out     0.000 Mb/s          8.150 Mb/s            9.344 GB

             ng1  in      0.000 Mb/s          0.000 Mb/s            2.688 MB
                  out     0.000 Mb/s          0.000 Mb/s           12.815 MB

             ng0  in      0.000 Mb/s          1.467 Mb/s          853.927 MB
                  out     0.000 Mb/s          2.548 Mb/s            3.896 GB

Looks like an overflow, a math error (perhaps at the stroke of 
midnight?), or an uncaught divide-by-zero. Since the peak rate 
calculation is done in userland, this isn't a critical bug; it 
won't cause a kernel panic. But it may be a good idea to see what 
might have caused it.

--Brett Glass