Just to help those not knowing about -k option:
-k Enable the HTTP KeepAlive feature, i.e., perform multiple requests within one HTTP session. Default is no KeepAlive

I'll do it but I guess the test will no longer be so relevant because I want to simulate different users.
Anyway, the question is in fact: is this http/https ratio normal?
If is it than I'll live with it, but if not then I might do something wrong.