diff --git a/api/ko-routes.go b/api/ko-routes.go
index 806456e..886e28e 100644
--- a/api/ko-routes.go
+++ b/api/ko-routes.go
@@ -169,6 +169,13 @@ func (api *API) setProgress(c *gin.Context) {
 		return
 	}
 
+	// Update Statistic
+	log.Info("[setProgress] UpdateDocumentUserStatistic Running...")
+	if err := api.DB.UpdateDocumentUserStatistic(rPosition.DocumentID, rUser.(string)); err != nil {
+		log.Error("[setProgress] UpdateDocumentUserStatistic Error:", err)
+	}
+	log.Info("[setProgress] UpdateDocumentUserStatistic Complete")
+
 	c.JSON(http.StatusOK, gin.H{
 		"document":  progress.DocumentID,
 		"timestamp": progress.CreatedAt,
@@ -285,6 +292,15 @@ func (api *API) addActivities(c *gin.Context) {
 		return
 	}
 
+	// Update Statistic
+	for _, doc := range allDocuments {
+		log.Info("[addActivities] UpdateDocumentUserStatistic Running...")
+		if err := api.DB.UpdateDocumentUserStatistic(doc, rUser.(string)); err != nil {
+			log.Error("[addActivities] UpdateDocumentUserStatistic Error:", err)
+		}
+		log.Info("[addActivities] UpdateDocumentUserStatistic Complete")
+	}
+
 	c.JSON(http.StatusOK, gin.H{
 		"added": len(rActivity.Activity),
 	})
diff --git a/database/manager.go b/database/manager.go
index b0f6093..fa25240 100644
--- a/database/manager.go
+++ b/database/manager.go
@@ -23,6 +23,9 @@ var ddl string
 //go:embed update_temp_tables.sql
 var tsql string
 
+//go:embed update_document_user_statistics.sql
+var doc_user_stat_sql string
+
 func NewMgr(c *config.Config) *DBManager {
 	// Create Manager
 	dbm := &DBManager{
@@ -60,6 +63,21 @@ func (dbm *DBManager) Shutdown() error {
 	return dbm.DB.Close()
 }
 
+func (dbm *DBManager) UpdateDocumentUserStatistic(documentID string, userID string) error {
+	// Prepare Statement
+	stmt, err := dbm.DB.PrepareContext(dbm.Ctx, doc_user_stat_sql)
+	if err != nil {
+		return err
+	}
+	defer stmt.Close()
+
+	// Execute
+	if _, err := stmt.ExecContext(dbm.Ctx, documentID, userID); err != nil {
+		return err
+	}
+	return nil
+}
+
 func (dbm *DBManager) CacheTempTables() error {
 	if _, err := dbm.DB.ExecContext(dbm.Ctx, tsql); err != nil {
 		return err
diff --git a/database/schema.sql b/database/schema.sql
index 39cf70c..c9a359e 100644
--- a/database/schema.sql
+++ b/database/schema.sql
@@ -136,7 +136,9 @@ CREATE TEMPORARY TABLE IF NOT EXISTS document_user_statistics (
     read_percentage REAL NOT NULL,
     percentage REAL NOT NULL,
     words_read INTEGER NOT NULL,
-    wpm REAL NOT NULL
+    wpm REAL NOT NULL,
+
+    UNIQUE(document_id, user_id) ON CONFLICT REPLACE
 );
 
 
@@ -325,6 +327,8 @@ current_progress AS (
             WHERE
                 dp.user_id = iga.user_id
                 AND dp.document_id = iga.document_id
+	    ORDER BY created_at DESC
+	    LIMIT 1
         ), end_percentage) AS percentage
     FROM intermediate_ga AS iga
     GROUP BY user_id, document_id
diff --git a/database/update_document_user_statistics.sql b/database/update_document_user_statistics.sql
new file mode 100644
index 0000000..5e99c45
--- /dev/null
+++ b/database/update_document_user_statistics.sql
@@ -0,0 +1,77 @@
+INSERT INTO document_user_statistics
+WITH intermediate_ga AS (
+    SELECT
+        ga1.id AS row_id,
+        ga1.user_id,
+        ga1.document_id,
+        ga1.duration,
+        ga1.start_time,
+        ga1.start_percentage,
+        ga1.end_percentage,
+
+        -- Find Overlapping Events (Assign Unique ID)
+        (
+            SELECT MIN(id)
+            FROM activity AS ga2
+            WHERE
+                ga1.document_id = ga2.document_id
+                AND ga1.user_id = ga2.user_id
+                AND ga1.start_percentage <= ga2.end_percentage
+                AND ga1.end_percentage >= ga2.start_percentage
+        ) AS group_leader
+    FROM activity AS ga1
+    WHERE
+        document_id = ?
+        AND user_id = ?
+),
+grouped_activity AS (
+    SELECT
+        user_id,
+        document_id,
+        MAX(start_time) AS start_time,
+        MIN(start_percentage) AS start_percentage,
+        MAX(end_percentage) AS end_percentage,
+        MAX(end_percentage) - MIN(start_percentage) AS read_percentage,
+        SUM(duration) AS duration
+    FROM intermediate_ga
+    GROUP BY group_leader
+),
+current_progress AS (
+    SELECT
+        user_id,
+        document_id,
+        COALESCE((
+            SELECT percentage
+            FROM document_progress AS dp
+            WHERE
+                dp.user_id = iga.user_id
+                AND dp.document_id = iga.document_id
+	    ORDER BY created_at DESC
+	    LIMIT 1
+        ), end_percentage) AS percentage
+    FROM intermediate_ga AS iga
+    GROUP BY user_id, document_id
+    HAVING MAX(start_time)
+)
+SELECT
+    ga.document_id,
+    ga.user_id,
+    MAX(start_time) AS last_read,
+    SUM(duration) AS total_time_seconds,
+    SUM(read_percentage) AS read_percentage,
+    cp.percentage,
+
+    (CAST(COALESCE(d.words, 0.0) AS REAL) * SUM(read_percentage))
+        AS words_read,
+
+    (CAST(COALESCE(d.words, 0.0) AS REAL) * SUM(read_percentage))
+    / (SUM(duration) / 60.0) AS wpm
+FROM grouped_activity AS ga
+INNER JOIN
+    current_progress AS cp
+    ON ga.user_id = cp.user_id AND ga.document_id = cp.document_id
+INNER JOIN
+    documents AS d
+    ON d.id = ga.document_id
+GROUP BY ga.document_id, ga.user_id
+ORDER BY wpm DESC;