When there is no stats for the past 7 days, don't show % changes

backend/src/api/explorer/statistics.api.ts

@@ -27,7 +27,7 @@ class StatisticsApi {
   public async $getLatestStatistics(): Promise<any> {
     try {
       const [rows]: any = await DB.query(`SELECT * FROM lightning_stats ORDER BY added DESC LIMIT 1`);
-      const [rows2]: any = await DB.query(`SELECT * FROM lightning_stats ORDER BY added DESC LIMIT 1 OFFSET 7`);
+      const [rows2]: any = await DB.query(`SELECT * FROM lightning_stats WHERE DATE(added) = DATE(NOW() - INTERVAL 7 DAY)`);
       return {
         latest: rows[0],
         previous: rows2[0],