pre_text: 15. Product Warranties The Company generally provides its customers with a one-year warranty regarding the manufactured quality and functionality of its products. For some limited products, the warranty period has been extended. The Company establishes warranty reserves based on its product history, current information on repair costs and annual sales levels. As of April 30, 2019, and 2018, respectively, changes in the carrying amount of accrued product warranty costs, reported in accrued expenses on the consolidated balance sheet, were as follows (in thousands):
table: 2019 2018
table: Balance at beginning of year $520 $557
table: Warranty costs incurred (398) (40)
table: Product warranty accrual 407 3
table: Balance at end of year $529 $520
question: Analyse this data from a financial earnings document. What is the change in beginning balance between 2018 and 2019?