how to mttr/mtbr

hi,
i'm still new in nagios.currently installed nagios core 3.2.3 on centos 5. pls help me to:
1- monitor and generate report for mttr and mtbr for each host
tqvm
i'm still new in nagios.currently installed nagios core 3.2.3 on centos 5. pls help me to:
1- monitor and generate report for mttr and mtbr for each host
tqvm