I ran indexphysical stats dmv and found 4 rows for 1 clustered index with depth 4 row having 80% fragmentation. Even after runnning, ALTER INDEX [INDEX] ON [dbo].

REBUILD WITH (FILLFACTOR=90, online=on). Fragmentation remains at 100%.

1. How to reduce this fragmentation in Clustered index at depth 4(in general for all depth rows)

2. How to reduce frag for NC which too are at 100%