Customer Contract - Related Balance Sheet Amounts
The Company generally invoices customers in annual installments payable in advance. The difference between the timing of revenue recognition and the timing of billings results in the recognition of unbilled accounts receivable or deferred revenue in the consolidated balance sheets. Amounts related to customer contract-related arrangements are included on the consolidated balance sheets as of August 1, 2018 and July 31, 2019 as follows (in thousands):
(1) The short- and long-term portions of this balance are reported in ‘Prepaid expenses and other current assets’ and ‘Other assets,’ respectively, on the consolidated balance sheets.
Unbilled accounts receivable
Unbilled accounts receivable includes those amounts that are unbilled due to agreed-upon contractual terms in which billing occurs subsequent to revenue recognition. This situation typically occurs when the Company transfers control of time-based software licenses to customers up-front, but invoices customers annually over the term of the license, which is typically two years.
During the fiscal year ended July 31, 2019, the Company transferred control of a ten year timebased license that resulted in $9.7 million of unbilled accounts receivable as of July 31, 2019, representing future billings in years two through ten of the license term.
Unbilled accounts receivable is classified as either current or non-current based on the duration of remaining time between the date of the consolidated balance sheets and the anticipated due date of the underlying receivables.
Contract costs
Contract costs consist of customer acquisition costs and costs to fulfill a contract, which includes commissions and their related payroll taxes, royalties, and referral fees. Contract costs are classified as either current or non-current based on the duration of time remaining between the date of the consolidated balance sheets and the anticipated amortization date of the associated costs.
The current portion of contract costs as of July 31, 2019 in the amount of $7.0 million is included in prepaid and other current assets on the Company’s consolidated balance sheets. The non-current portion of contract costs as of July 31, 2019 in the amount of $23.4 million is included in other assets on the Company’s consolidated balance sheets. The Company amortized $5.5 million of contract costs during the fiscal year ended July 31, 2019.
Deferred revenue
Deferred revenue consists of amounts that have been invoiced and for which the Company has the right to bill, but that have not been recognized as revenue because the related goods or services have not been transferred. Deferred revenue that will be realized during the 12-month period following the date of the consolidated balance sheets is recorded as current, and the remaining deferred revenue is recorded as non-current.
During the fiscal year ended July 31, 2019, the Company recognized revenue of $112.2 million related to the Company’s deferred revenue balance as of August 1, 2018.

Beginning balance as of
August 1, 2018 as adjusted
Ending balance as of July 31, 2019 as reported
Unbilled accounts receivable, net
$ 28,762
46,103
Contract costs, net(1)
12,932
30,390
Deferred revenue, net
(141,685)
(131,831)


Question: Analyse this data from a financial earnings document. What was the average Contract costs, net for 2018 and 2019?
Choices:
0
-50720
21661
-21661
15251
Correct choice index: 2