Consider CSMA/CD LAN with bandwidth 10 Mbps and propagation delay of 5 $musec$. Repeaters are not allowed in this system. Data frames are 512 bits long, including 32 bits of the header, checksum, and other overhead. The first-bit slot after a successful transmission is reserved for the receiver to capture the channel in order to send a 32-bit acknowledgment frame. The effective data rate of the network is _______(in Mbps). (Excluding overhead, assuming that there are no collisions)