total session number in the Statistics Report page

[Alon M]

Hi , 
i was wondering is some one could explain why there is always a small difference
between the 
total session on our single listener called -     "pm" -      600885
to the back end server of that listener  called -"localPM"    600845

below is the config :

global
    log         127.0.0.1 local0
    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    stats socket    /tmp/haproxy level admin
    user        haproxy
    group       haproxy
    daemon
defaults
    mode        http
    log         global
    timeout connect 1000 
    timeout client 20000
    timeout server 2000
    maxconn     60000
    retries     3
    option httpclose # Disable Keepalive
    option      httplog
listen pm 192.168.181.43:8080
timeout http-request 3000
stats uri /haproxy
balance roundrobin # Load Balancing algorithm
option forwardfor header pm-forwarded 
server localPM 192.168.181.43:9090



thanks 

Alon