pre_text: Services Teradyne services consist of extended warranties, training and application support, service agreement, post contract customer support (“PCS”) and replacement parts. Each service is recognized based on relative standalone selling price. Extended warranty, training and support, service agreements and PCS are recognized over time based on the period of service. Replacement parts are recognized at a point in time upon transfer of control to the customer. Teradyne does not allow customer returns or provide refunds to customers for any products or services. Teradyne products include a standard 12-month warranty. This warranty is not considered a distinct performance obligation because it does not obligate Teradyne to provide a separate service to the customer and it cannot be purchased separately. Cost related to warranty are included in cost of revenues when product revenues are recognized. As of December 31, 2019 and 2018, deferred revenue and customer advances consisted of the following and are included in the short and long-term deferred revenue and customer advances:
table: 2019 2018
table: (in thousands)
table: Maintenance, service and training $63,815 $58,362
table: Extended warranty 30,677 27,422
table: Customer advances, undelivered elements and other 56,358 24,677
table: Total deferred revenue and customer advances $150,850 $110,461
question: Analyse this data from a financial earnings document. What was the change in Extended warranty from 2018 to 2019?