Sankey with circular links

s → s Index: 0sd → s Index: 1bt → s Index: 2pb → s Index: 3s → sd Index: 4pb → bt Index: 5s → bt Index: 6start → bt Index: 7pg → bt Index: 8start → pb Index: 9bt → pb Index: 10bt → pg Index: 11startstart 22314btbt 67249pbpb 36086pgpg 12442sdsd 22305ss 78368