diff --git a/content/descriptive_statistics/_index.md b/content/descriptive_statistics/_index.md
index 7d2f2bf..f38666b 100755
--- a/content/descriptive_statistics/_index.md
+++ b/content/descriptive_statistics/_index.md
@@ -51,7 +51,7 @@ Für eine erste Demo bist Du verantwortlich:
 - Berechne 2-3 Statistiken und erstelle 2-3 Visualisierungen basierend auf den Informationen im [Datensatz](/2023-2024-ZK_Data_Librarian_Modul_3/organisation/dataset/).
 - Nutze `pandas` zur Berechnung der Statistiken und `seaborn` für die Visualisierungen.
 
-Lade bis spätestens **24.03.23** Deinen Report in Form eines *Jupyter Notebooks* in der [Dateiablage](https://zbiw.th-koeln.de/moodle/mod/assign/view.php?id=12281&forceview=1) in Moodle hoch.
+Lade bis spätestens **18.03.24** Deinen Report in Form eines *Jupyter Notebooks* in der [Dateiablage](https://zbiw.th-koeln.de/moodle/mod/assign/view.php?id=12281&forceview=1) in Moodle hoch.
 
 {{% /customnotice %}}
 
diff --git a/content/solutions.files/2.8.solutions_na.ipynb b/content/solutions.files/2.8.solutions_na.ipynb
index bdb8135..58aa6e0 100644
--- a/content/solutions.files/2.8.solutions_na.ipynb
+++ b/content/solutions.files/2.8.solutions_na.ipynb
@@ -80,6 +80,136 @@
     "df.isna().sum()"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "0              keine Angabe\n",
+       "1              keine Angabe\n",
+       "2            45 to 54 years\n",
+       "3              keine Angabe\n",
+       "4              keine Angabe\n",
+       "                ...        \n",
+       "436285       35 to 44 years\n",
+       "436286       10 to 19 years\n",
+       "436287       60 to 64 years\n",
+       "436288       35 to 44 years\n",
+       "436289    75 years and over\n",
+       "Name: Age Range, Length: 436290, dtype: object"
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df['Age Range'].fillna(\"keine Angabe\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "Patron Type Code                    0\n",
+       "Patron Type Definition              0\n",
+       "Total Checkouts                     0\n",
+       "Total Renewals                      0\n",
+       "Age Range                         912\n",
+       "Home Library Code                   2\n",
+       "Home Library Definition             0\n",
+       "Circulation Active Month        39513\n",
+       "Circulation Active Year         39513\n",
+       "Notice Preference Code          42989\n",
+       "Notice Preference Definition        0\n",
+       "Provided Email Address              0\n",
+       "Year Patron Registered              0\n",
+       "Within San Francisco County      1207\n",
+       "dtype: int64"
+      ]
+     },
+     "execution_count": 5,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df.isna().sum()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "2            45 to 54 years\n",
+       "5            45 to 54 years\n",
+       "6            55 to 59 years\n",
+       "7            45 to 54 years\n",
+       "9            45 to 54 years\n",
+       "                ...        \n",
+       "436285       35 to 44 years\n",
+       "436286       10 to 19 years\n",
+       "436287       60 to 64 years\n",
+       "436288       35 to 44 years\n",
+       "436289    75 years and over\n",
+       "Name: Age Range, Length: 435378, dtype: object"
+      ]
+     },
+     "execution_count": 6,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df['Age Range'].dropna()"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [
+    {
+     "data": {
+      "text/plain": [
+       "Patron Type Code                    0\n",
+       "Patron Type Definition              0\n",
+       "Total Checkouts                     0\n",
+       "Total Renewals                      0\n",
+       "Age Range                         912\n",
+       "Home Library Code                   2\n",
+       "Home Library Definition             0\n",
+       "Circulation Active Month        39513\n",
+       "Circulation Active Year         39513\n",
+       "Notice Preference Code          42989\n",
+       "Notice Preference Definition        0\n",
+       "Provided Email Address              0\n",
+       "Year Patron Registered              0\n",
+       "Within San Francisco County      1207\n",
+       "dtype: int64"
+      ]
+     },
+     "execution_count": 7,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "df.isna().sum()"
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 4,