diff --git a/public/include/classes/statistics.class.php b/public/include/classes/statistics.class.php
index 10faf83a..7e511749 100644
--- a/public/include/classes/statistics.class.php
+++ b/public/include/classes/statistics.class.php
@@ -152,8 +152,8 @@ class Statistics {
     if ($this->getGetCache() && $data = $this->memcache->get(__FUNCTION__)) return $data;
     $stmt = $this->mysqli->prepare("
       SELECT
-        IFNULL(SUM(IF(our_result='Y', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), difficulty), 0)), 0) AS valid,
-        IFNULL(SUM(IF(our_result='N', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), difficulty), 0)), 0) AS invalid
+        IFNULL(SUM(IF(our_result='Y', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS valid,
+        IFNULL(SUM(IF(our_result='N', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS invalid
       FROM " . $this->share->getTableName() . "
       WHERE UNIX_TIMESTAMP(time) >IFNULL((SELECT MAX(time) FROM " . $this->block->getTableName() . "),0)");
     if ( $this->checkStmt($stmt) && $stmt->execute() && $result = $stmt->get_result() )
@@ -174,8 +174,8 @@ class Statistics {
     if ($this->getGetCache() && $data = $this->memcache->get(__FUNCTION__)) return $data;
     $stmt = $this->mysqli->prepare("
       SELECT
-        IFNULL(SUM(IF(our_result='Y', IF(s.difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), s.difficulty), 0)), 0) AS valid,
-        IFNULL(SUM(IF(our_result='N', IF(s.difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), s.difficulty), 0)), 0) AS invalid,
+        IFNULL(SUM(IF(our_result='Y', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS valid,
+        IFNULL(SUM(IF(our_result='N', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS invalid,
         u.id AS id,
         u.username AS username
       FROM " . $this->share->getTableName() . " AS s,
@@ -200,8 +200,8 @@ class Statistics {
     if ($this->getGetCache() && $data = $this->memcache->get(__FUNCTION__ . $account_id)) return $data;
     $stmt = $this->mysqli->prepare("
       SELECT
-        IFNULL(SUM(IF(our_result='Y', IF(s.difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), s.difficulty), 0)), 0) AS valid,
-        IFNULL(SUM(IF(our_result='N', IF(s.difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)), s.difficulty), 0)), 0) AS invalid
+        IFNULL(SUM(IF(our_result='Y', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS valid,
+        IFNULL(SUM(IF(our_result='N', IF(difficulty=0, pow(2, (" . $this->config['difficulty'] . " - 16)) - 1, difficulty), 0)), 0) AS invalid
       FROM " . $this->share->getTableName() . " AS s,
            " . $this->user->getTableName() . " AS u
       WHERE