pre_text: In 2019 and 2018, we had pre-tax losses of $19,573 and $25,403 respectively, which are available for carry forward to offset future taxable income. We made determinations to provide full valuation allowances for our net deferred tax assets at the end of 2019 and 2018, including NOL carryforwards generated during the years, based on our evaluation of positive and negative evidence, including our history of operating losses and the uncertainty of generating future taxable income that would enable us to realize our deferred tax assets. Deferred tax assets (liabilities) consist of the following: In assessing the realization of deferred tax assets, management considers whether it is more likely than not that a portion of the net deferred assets will not be realized. The ultimate realization of the net deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences become deductible. Based on the available objective evidence, management believes it is more likely than not that the net deferred tax assets at December 31, 2019 will not be realizable. Accordingly, management has maintained a full valuation allowance against its net deferred tax assets at December 31, 2019. The net change in the total valuation allowance for the 12 months ended December 31, 2019 was an increase of $1,816.
table: As of As of
table: December 31, 2019 December 31, 2018
table: Deferred tax assets:
table: Reserves and accruals $62 $45
table: Research and development credits and other credits 1,730 1,635
table: Net operating loss carry forward 27,907 25,733
table: Stock based compensation 8,402 8,857
table: Other 11 26
table: Total deferred tax assets 38,112 36,296
table: Valuation allowance (38,112) (36,296)
table: Deferred tax assets after valuation allowance — —
table: Total deferred tax liability — —
table: Net deferred tax assets (liabilities) $— $—
question: Analyse this data from a financial earnings document. What is the percentage change in the net operating loss carry forward from 2018 to 2019?