On the graph, how can there be more replies per second (the y axis) than requests (the x axis)? Look at the graph at x=80 (actually, it's slightly under, maybe

On the graph, how can there be more replies per second (the y axis) than requests (the x axis)? Look at the graph at x=80 (actually, it's slightly under, maybe 79). There are up to 85 replies.