pre_text: The net deferred tax asset is classified on the consolidated balance sheets as follows (in thousands): We have various tax attribute carryforwards which include the following: • Foreign federal and local gross net operating loss carryforwards are $61.6 million, of which $47.0 million have no expiration date and $14.6 million have various expiration dates beginning in fiscal 2020. Among the total of $61.6 million foreign net operating loss carryforwards, a valuation allowance of $31.7 million has been provided for certain jurisdictions since the recovery of the carryforwards is uncertain. U.S. federal and certain state gross net operating loss carryforwards are $14.0 million and $30.7 million, respectively, which were acquired from our acquisitions. A full valuation allowance against certain other state net operating losses of $30.7 million has been recorded. California gross net operating loss carryforwards are $2.8 million and are scheduled to expire beginning in fiscal 2032. • U.S. federal R&D credit carryforwards of $35.4 million are scheduled to expire beginning in fiscal 2025. California R&D credit carryforwards of $32.2 million have no expiration date. A total of $27.1 million valuation allowance, before U.S. federal benefit, has been recorded against California R&D credit carryforwards of $32.2 million since the recovery of the carryforwards is uncertain. Other states R&D credit carryforwards of $3.9 million are scheduled to expire beginning in fiscal 2020. A valuation allowance totaling $2.7 million, before U.S. federal benefit, has been recorded against certain state R&D credit carryforwards of $3.9 million since the recovery of the carryforwards is uncertain. • U.S. federal foreign tax credit carryforwards of $51.9 million are scheduled to expire beginning in fiscal 2022.
table: Fiscal year-end
table: 2019 2018
table: Non-current deferred income tax assets $87,011 $64,858
table: Non-current deferred income tax liabilities (27,785) (26,339)
table: Net deferred tax assets $59,226 $38,519
question: Analyse this data from a financial earnings document. What was the change in Net deferred tax assets from 2018 to 2019?