. other regulatory charges increased primarily due to over-recovery of capacity charges related to the grand gulf rate rider and the cessation of the grand gulf accelerated recovery tariff that was suspended in july 2003 . other income statement variances 2004 compared to 2003 other operation and maintenance expenses increased primarily due to : 2022 an increase of $ 6.6 million in customer service support costs ; and 2022 an increase of $ 3.7 million in benefit costs