querying backupset to check compression ratio

SELECT  b.database_name 'Database Name',  

CONVERT (BIGINT, b.backup_size / 1048576 ) 'UnCompressed Backup Size (MB)',  

CONVERT (BIGINT, b.compressed_backup_size / 1048576 ) 'Compressed Backup Size (MB)',  CONVERT (NUMERIC (20,2), (CONVERT (FLOAT, b.backup_size) /  CONVERT (FLOAT, b.compressed_backup_size))) 'Compression Ratio',

DATEDIFF (SECOND, b.backup_start_date, b.backup_finish_date) 'Backup Elapsed Time (sec)'  

FROM  msdb.dbo.backupset b  

WHERE  DATEDIFF (SECOND, b.backup_start_date, b.backup_finish_date) > 0  

AND b.backup_size > 0  

ORDER BY  b.backup_finish_date DESC