pre_text: Deferred income taxes arise from temporary differences between the tax basis of assets and liabilities and their reported amounts in the financial statements. A summary of the tax effect of the significant components of deferred income taxes is as follows (in thousands): At December 31, 2019, we had state and foreign net operating losses of approximately $12.2 million and $7.9 million, respectively. The state net operating losses expire beginning 2027 through 2038. We recorded a full valuation allowance against the foreign net operating losses and a partial valuation allowance against the state net operating losses, as we do not believe those losses will be fully utilized in the future.
table: December 31,
table: 2019 2018
table: Goodwill and other intangibles $136,882 $114,532
table: Lease arrangements 31,128 —
table: Property and equipment 13,270 8,168
table: Unbilled receivables - IRC Section 481(a) 5,878 8,816
table: Gross deferred tax liabilities 187,158 131,516
table: Lease obligations (34,146) —
table: Retirement and other liabilities (18,614) (20,707)
table: Allowance for potential contract losses and other contract reserves (2,205) (1,681)
table: Foreign and state operating loss carryforwards (2,239) (1,709)
table: Less: Valuation allowance 1,828 1,537
table: Gross deferred tax assets (55,376) (22,560)
table: Net deferred tax liabilities $131,782 $108,956
question: Analyse this data from a financial earnings document. What is the proportion of the sum of lease arrangements and unbilled receivables over gross deferred tax liabilities on December 31, 2019?