What this is
Set comparison of the names between 主なお取引先 and ロッテなど（五十音順） in archive-A/brand-sheet-202508.txt (l.187-190) and brand-sheet-202608.txt (l.196-200); 丸美屋 (2025) and 丸美屋食品 (2026) treated as the same firm.
The values
- N 2025: 20
- N 2026: 19
- Retained: 16
- Added: 花王, コスモスホテルマネジメント, サントリービバレッジ&フード
- Dropped: 資生堂, ダスキン（ミスタードーナツ）, P&G, ファミリーマート
- Retention: 80%
Some detail is too fine to show here; it is kept in the trainer’s notes.
Where it comes from
Our calculation from other figures in the trainer’s notes.
Show the working
- 20 (2025) - 4 dropped = 16 retained
- 16 + 3 added = 19 (2026)
- 16/20 = 80.0% retained
- 3 + 4 = 7 changes