question about dbms_space.object_growth_trend

I issued the following query:

select timepoint, space_usage, space_alloc, quality from table(dbms_space.object_growth_trend('QC','ACT','TABLE'  ) );

It returned me 36 rows. I am not sure how I should interpret the results.

TIMEPOINT                 SPACE_USAGE SPACE_ALLOC QUALITY
------------------------- ----------- ----------- --------------------
05-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

06-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

07-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

08-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

TIMEPOINT                 SPACE_USAGE SPACE_ALLOC QUALITY
------------------------- ----------- ----------- --------------------

09-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

10-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

11-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

12-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED

TIMEPOINT                 SPACE_USAGE SPACE_ALLOC QUALITY
------------------------- ----------- ----------- --------------------
 AM

13-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

14-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

15-DEC-11 09.05.45.377557      145209     5242880 INTERPOLATED
 AM

TIMEPOINT                 SPACE_USAGE SPACE_ALLOC QUALITY