Full marks for taking the experimental data.
Less marks because, like all of us, you only have measurements for when things were going wrong and don't know what normal looks like.
I will not question Mr B's expert and experienced contribution but add this account of my own, to reassure you or add to your doubts:
January 2015 new WRX, with new battery.
November 2015 went to Australia for a month [no, not in Suby]. Car turns over fine on return, but then left it a few more days before actually driving. Battery flat. Realised I really should have disabled the remote locking to