Hoe to find 'how much space is saved by looking at ALREADY compressed table?'

 Hi Guys,
I have a table in 10gR2 (on IBM with 8K block) and it has following details :

Size                    : 24 GB
Rows                  : 82223160
Blocks                : 804,318
AVG_ROW_LEN : 180
PARTITIONS      : 25 partitions(all the partitions all in seperate individual tablespaces)

My question is :
I want to know how much is actually this table would have taken if it would have been UNCOMPRESSED ?
   OR
How much % of data compression is there ?

If you need then Table script is as follows :

CREATE TABLE TEST
(
  PERIOD_ID                     NUMBER,
  BUSINESS_AREA_ID              NUMBER,
  SOURCE_SYSTEM_ID              NUMBER,
  SUBSCRIPTION_ID               NUMBER,
  ACCOUNT_ID                    NUMBER,
  PRODUCT_OFFER_ID              NUMBER,
  KURT_ID_OWNER                 NUMBER,