pre_text: Accounts Receivable and Allowance for Doubtful Accounts The majority of our accounts receivable are derived from sales to large multinational semiconductor manufacturers throughout the world, are recorded at their invoiced amount and do not bear interest. In order to monitor potential credit losses, we perform ongoing credit evaluations of our customers' financial condition. An allowance for doubtful accounts is maintained based upon our assessment of the expected collectability of all accounts receivable. The allowance for doubtful accounts is reviewed and assessed for adequacy on a quarterly basis. We take into consideration (1) any circumstances of which we are aware of a customer's inability to meet its financial obligations and (2) our judgments as to prevailing economic conditions in the industry and their impact on our customers. If circumstances change, and the financial condition of our customers is adversely affected and they are unable to meet their financial obligations, we may need to take additional allowances, which would result in an increase in our operating expense. Activity related to our allowance for doubtful accounts receivable was as follows (in thousands):
table: Fiscal Year Ended
table: December 28, 2019 December 29, 2018 December 30, 2017
table: Balance at beginning of year $185 $200 $299
table: Charges (reversals) to costs and expenses 37 (15) (99)
table: Balance at end of year $222 $185 $200
question: Analyse this data from a financial earnings document. What is the change in allowance Balance at beginning of year from Fiscal Year Ended December 28, 2019 to December 29, 2018?