pre_text: As lessee — We lease restaurants and other facilities, which generally have renewal clauses of 1 to 20 years exercisable at our option. In some instances, these leases have provisions for contingent rentals based upon a percentage of defined revenues. Many of our restaurant and other facility leases also have rent escalation clauses and require the payment of property taxes, insurance, and maintenance costs. We also lease certain restaurant and office equipment. Minimum rental obligations are accounted for on a straight-line basis over the term of the initial lease, plus lease option terms for certain locations. The components of rent expense were as follows in each fiscal year (in thousands):
table: 2019 2018 2017
table: Minimum rentals $184,587 $184,106 $185,696
table: Contingent rentals 2,255 2,221 2,419
table: Total rent expense 186,842 186,327 188,115
table: Less rental expense on subleased properties (170,651) (162,640) (145,728)
table: Net rent expense $16,191 $23,687 $42,387
question: Analyse this data from a financial earnings document. What is the difference in net rent expense between 2017 and 2018?