I've read two good books this year.
Oil prices have gone up again!
I've repaired the car.
She's been working here for ages.
I've never tried African food.
I've spoken to him recently.
I've been trying to solve this issue.
Result of things completed "so far"
A completed activity (time not given)
Talking about visible change
Showing final effect (task completion)
A continuous activity which started in the past and hasn't finished yet.
Unfinished activity
General life experience (time not stated)