diff --git a/persistent_auditor.py b/persistent_auditor.py
index 6cde9f9..cb8f6ce 100644
--- a/persistent_auditor.py
+++ b/persistent_auditor.py
@@ -47,6 +47,7 @@ def load_inventory():
 inventory = load_inventory()
 total_units = 0
 failed_attempts = 0
+transaction_history = []
 
 print("=== Stock Auditor ===")
 print("Type 'quit' to exit.\n")
@@ -59,6 +60,7 @@ while True:
 
     tax = calculate_tax(quantity)
 
+    transaction_history.append(quantity)
     inventory = process_delivery(inventory, quantity)
     total_units = process_delivery(total_units, quantity)