/proc/self/mountstats
device 192.168.50.103:/srv/homes mounted on /a with fstype nfs statvers=1.1
	opts:	rw,vers=3,rsize=262144,wsize=262144,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,hard,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=192.168.50.103,mountvers=3,mountport=49654,mountproto=udp,local_lock=none
	age:	788

The age field is how many seconds this particular mount has been mounted.

       /proc/self
              When a process accesses this magic symbolic link, it
              resolves to the process's own /proc/[pid] directory