What does it mean? What do I do about it?
Percentage of records that have one or more fragments (the record is stored in pieces across multiple blocks). Fragmented records take additional IO operations to read and write.
Investigate the cause of fragmentation and mitigate it. A dump & load is probably required.
Fragmentation may be due to inappropriate rows-per-block or mismatches with the create and toss limits. It often occurs when a record grows after its initial creation. When the record needs to expand, there is not enough space in the original block, and space must be allocated in another block for the overflow.