Throughput calculation

i have F5 LTM , 2 G of traffic is shownon monitoring tool to be sent to F5 , but i can see from GUI dashboard that Throuput is 5.3 G

 

plaese note that servers behind F5 have both in & out legs connected to F5

 

so is this reason why throuput is multiplies of 2 g , & if yes why it is not Just 2*2 = 4 G ?