What does metric Session Current (scur) signify for backend

Hi,

Could someone please explain what scur mean for backend.

I am generating constant load with 100 connections using wrk. For frontend this metric correctly comes to be 100, but for backend, it occasionally comes to be 1 and then 0 for whole duration.
While checking at the server (using ss command), I see constant 100 connections being made from HAProxy instance to this server. My understanding was that this metric gives the current number of active connections to the server (which should have been 100). But since it is giving 0 for whole duration of load generation, I am getting confused.

Load generation:

wrk -c 100 -t5 -d1m -R1000 http://VIP

Config

global
log /dev/log local0
log /dev/log local1 notice
chroot /var/lib/haproxy
user haproxy
group haproxy
daemon
#maxconn 65536

defaults
log global
mode http
http-reuse safe
option http-keep-alive
no log
timeout connect 5000
timeout client 50000
timeout server 50000
errorfile 400 /etc/haproxy/errors/400.http
errorfile 403 /etc/haproxy/errors/403.http
errorfile 408 /etc/haproxy/errors/408.http
errorfile 500 /etc/haproxy/errors/500.http
errorfile 502 /etc/haproxy/errors/502.http
errorfile 503 /etc/haproxy/errors/503.http
errorfile 504 /etc/haproxy/errors/504.http

frontend test
bind :80
mode http
maxconn 65536
default_backend nginx

backend nginx
mode http
balance leastconn
server 10.30.10.110 10.30.10.110:81 weight 255

I am using HAProxy 2.0.14 for the test. Also, is “connect” metric the only way to get the actual number of connections being made to the backend?