SNMP OID for Route Table Size

Looking for the OID for the route table size.

MX480 on 15.1R6.7

IPv4 Route Tables:
Index         Routes     Size(b)
--------  ----------  ----------
Default       725254    98634540

I want the second number. I can't find it anywhere. Loaded all the MIBs in a browser and searched. Searched through Juniper's MIB explorer. I can get the PFE memory utilization, which is helpful, but I'd like to see the 725254 number as well.

Anybody happen to know the OID or the jnx name for this OID?

Thanks