People who train want to be able to see how things add up. The charts in "Reports" are useless without numeric totals that add up 7 days, 30 days, etc. They may look pretty, but are so stripped down, without barely any numbers and require the user to pull out a calculator to see what the totals are. All they do is provide a visual - which doesn't help anything, really. Sorry to rant and hopefully I am missing something. But Garmin Conncet doesn't help me one bit in terms if being able to see how much training I've accumulated each week or month, without having to use a different tool, nor does it tell me how much time I've been in my HR zones weekly, monthly or yearly. One would think that these are pretty important features for the most basic of athlete. Someone set me straight, please!
You can get reports for last 7 days, last week, last 30 days, last month, etc.
If you want to analyze your HR trends over time, you could use a free site like runalyze.com. It doesn't give you exactly what you want, but it can show a scatterplot of your average HR (per activity), as well as the trending average (of avg) over time.
(Unfortunately with runalyze you have to import your data manually. There are ways to grab all your activities from GC, but it's a bit of a pain.)