Pieces of Time for low levels

I got 2 in 2 hours on 1x at Memory 3 and 4. :f6: or am I just lucky?

It's possible...

I found 11 while doing the quests >_>
(I did Memory 1 in a party and didn't get any)
Memory 2, 3: 1
Memory 4: 3
Regret 1: 1
Regret 2: 2
(I soloed Regret 3, 4, Oblivion 1, 2, 3 and didn't get any)
Oblivion 4: 3

I'd say Oblivion is best and Regret is worst but that's just my personal experience... I'd guess I spent about 2:45 at Oblivion 4 and got 4 Pieces of Time (killed maybe 1300?)