RQM - Execution Trend report question

CLM 502

I have a question about the Execution Trend report:

I have read the help and this chart and I need some clarification. If I have 450 test cases each worth one point. So 450 TCERs each worth one point as well.

My chart says:
9/13/15 - Complete = 254 Attempted = 334
9/20/15 - Complete = 314 Attempted = 344

Attempted:
I read the help, but what does this mean EXACTLY. Is the Attempted telling me that out of 450 TCERs, I have only Attempted 344 unique cases as of 9/20? Or is it telling me that the tester did 334 unique attempts the week of 9/13 and then 344 during 9/20 or did the tester just do 10 tests in one week. It's hard to see b/c the week of 9/20, the number of complete grows, more than the amount of Attempted (19) from 9/13-9/20.

(Update - forgot to add chart)