I have a LOB tablespace a around 20gb in space in which all lob's are placed in this tablespace. The average row size is 109 bytes. How do I best manage not using so much space without a decrease in performance?

Block size =4096 and my chunk size is 8192

CREATE TABLESPACE "XDBLOB_1"
LOGGING
DATAFILE 'X:\ORADATA\XDB02\XDBLOB_1_GONZO08.DBF' SIZE
16777208K REUSE AUTOEXTEND
ON NEXT 10240K MAXSIZE 16383M,
'X:\ORADATA\XDB02\XDBLOB_1_LOBDB_2.DBF' SIZE 9280M REUSE
AUTOEXTEND
ON NEXT 10240K MAXSIZE 16383M EXTENT MANAGEMENT LOCAL
SEGMENT SPACE MANAGEMENT AUTO