if F5 routing based on bandwidth dynamic?

i have two line to ISP, one have bandwidth 40M called ISPA, another have bandwidth 100M called ISPB, and use LC,GTM execuate inbound and outbound routing according to iRules association class. now i have a question, if F5 can choose the way by bandwidth. When the bandwidth of the ISPA reached 90%, switching to the ISPB. When the bandwidth is less than 90%, switching to ISPA. F5 whether can implement it ?