pre_text: Deferred Revenue The opening balances of current and long-term deferred revenue were $30,694 and $1,352, respectively, as of January 1, 2018. Expressed in US $000's except share and per share amounts
table: Years ended
table: December 31, 2019 December 31, 2018
table: $ $
table: Current portion 56,691 39,180
table: Long term portion 5,969 1,881
table: 62,660 41,061
question: Analyse this data from a financial earnings document. How much has long-term deferred revenue changed from January 1, 2018 to December 31, 2018?