diff --git a/notebooks/statistics.ipynb b/notebooks/statistics.ipynb
index 44a823e..7352aaa 100644
--- a/notebooks/statistics.ipynb
+++ b/notebooks/statistics.ipynb
@@ -175,6 +175,39 @@
     "print(f\"P-value for SB in 60-70 vs others: {p_sb}\")"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "# Change from group to category\n",
+    "age_categories = [0, 10, 20, 30, 40, 50, 60, 70, 80, 90]\n",
+    "df_dgc['age_group'] = pd.cut(df_dgc['age'], bins=age_categories)\n",
+    "corr_matrix_age_diag= pd.crosstab(df_dgc['age_group'], df_dgc['diag'])\n",
+    "\n",
+    "# Chi-square test\n",
+    "chi2, p, _, _ = chi2_contingency(corr_matrix_age_diag)\n",
+    "\n",
+    "# Difference between observed and expected frequencies\n",
+    "print(f\"Chi-Square Statistic: {chi2}\")\n",
+    "print(f\"P-value: {p}\")\n",
+    "\n",
+    "# Check if AFIB (atrial fibrillation /atrial flutter) has a significantly higher frequency in the 70-80 age group\n",
+    "afib_70_80 = corr_matrix_age_diag.loc[pd.Interval(70, 80, closed='right'), 'AFIB']\n",
+    "afib_other = corr_matrix_age_diag.drop(pd.Interval(70, 80, closed='right')).sum()['AFIB']\n",
+    "total_70_80 = corr_matrix_age_diag.loc[pd.Interval(70, 80, closed='right')].sum()\n",
+    "total_other_70_80 = corr_matrix_age_diag.drop(pd.Interval(70, 80, closed='right')).sum().sum()\n",
+    "\n",
+    "# Frequency table for the specific Chi-Square test\n",
+    "observed = [[afib_70_80, total_70_80 - afib_70_80], [afib_other, total_other_70_80 - afib_other]]\n",
+    "chi2_afib, p_afib = chi2_contingency(observed)[:2]\n",
+    "\n",
+    "\n",
+    "print(f\"Chi-Square Statistic for AFIB in 70-80 vs others: {chi2_afib}\")\n",
+    "print(f\"P-value for AFIB in 70-80 vs others: {p_afib}\")"
+   ]
+  },
   {
    "cell_type": "markdown",
    "metadata": {},