Monitoring the activity of tape drive with SCSI generic driver (sg)

I would like to monitor statistics (transfer rate, byte/sec) for each LTO tape drive connected to Linux system. I understand that tapestat command can exactly do this, but this shows the activity of tape driver:/dev/st only. In other words, if we write/read data using SCSI generic driver: /dev/sg, this command shows nothing. Indeed, when reading/writing data with ITDT from IBM that uses the generic driver, I can not see any statistics. Is there any good ways to monitor transfer rate even with SCSI generic driver?