pre_text: Deferred Revenue The following table summarizes contract liabilities which are shown as deferred revenue (in thousands): Total deferred revenue increased primarily due to the extended duration period of new maintenance contracts during fiscal year 2019.
table: June 30,
  2019 June 30,
  2018
table: Deferred maintenance $192,955 $164,986
table: Other deferred revenue   10,287 9,539
table: Total deferred revenue, net   203,242 174,525
table: Less: current portion   144,230 130,865
table: Non-current deferred revenue, net $59,012 $43,660
question: Analyse this data from a financial earnings document. What was the change in the amount of Deferred maintenance between 2018 and 2019?