HAProxy community

How does HAProxy behave when algorithm is least connection and each backend server has equal number of connection from HAProxy

I have observed that for http-reuse set as safe and when all the servers in backend has 1 connection each with HAProxy. With least conn as the load balancing algorithm, how does HAProxy distribute incoming requests?
In my setup each backend server takes same amount of time for request processing.

PS: I observed different number of requests sent to each backend servers after load generation. So got curious.