diff --git a/data/pmcs/202101-ME.xls b/data/pmcs/202101-ME.xls
new file mode 100644
index 0000000..2b99e79
--- /dev/null
+++ b/data/pmcs/202101-ME.xls
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:50fe351a0ce89e6404bf913c07ef9efccc02b8be9a224b37a68d7d0f2493f6c5
+size 3468288
diff --git a/milestones/burndown.py b/milestones/burndown.py
index 8c7411c..441eecf 100644
--- a/milestones/burndown.py
+++ b/milestones/burndown.py
@@ -50,13 +50,23 @@ def burndown(args, milestones):
     plt.plot(month_starts, model, label="Baseline")
 
     achieved_months = [mnth for mnth in month_starts if mnth <= last_achieved_month]
-    achieved_months.append(
-        datetime(
-            achieved_months[-1].year,
-            achieved_months[-1].month + 1,
-            achieved_months[-1].day,
+    # Need to acount for year wrap
+    if achieved_months[-1].month == 12:
+        achieved_months.append(
+            datetime(
+                achieved_months[-1].year + 1,
+                1,
+                achieved_months[-1].day,
+                )
+        )
+    else:
+        achieved_months.append(
+            datetime(
+                achieved_months[-1].year,
+                achieved_months[-1].month + 1,
+                achieved_months[-1].day,
+            )
         )
-    )
     plt.plot(achieved_months, actual[: len(achieved_months)], label="Achieved")
 
     plt.xlabel("Date")