Received eQSL's with very low power

The last weeks I answered a lot of eQSL's.
In the INBOX I found many eQSL of QSO's, that were made with 5 W down to 5 milliwatt.

In many contest QSO's, I often reduce to the lowest possible power.
I start with a power that is probably to low.
When my signal is not heard, I increase my power with a small step.

I show here, a few eQSL's that were made with 36 mW and 80 mW and an Inverted V

36 milliwatt 

F5IN  -  36 mW - 295 miles - 8200 Miles per Watt

F6HKA  -  36 mW - 464 miles - 12886 Miles per Watt

80 milliwatt 

OH2BV  -  80 mW - 953 miles - 19111 Miles per Watt

ES5Q  -  80 mW - 955 miles - 15117 Miles per Watt

R7AB  -  80 mW - 1602 miles - 20020 Miles per Watt

My FT-817 makes 360 mW on the lowest setting.
I reduce 360 mW with an attenuator of 10 dB to 36 mW.
On the setting for 1 W, my FT-817 gives 800 mW.
After the 10 dB attenuator, only 80 mW goes to the inverted V.