pre_text: 14. Selected Quarterly Financial Data (Unaudited) Selected quarterly financial data for 2019 and 2018 is as follows (in thousands, except per share amounts):
table: Quarter Ended
table: March 31, June 30, September 30, December 31,
table: 2019 2019 2019 2019
table: Revenue $50,290 $49,189 $52,833 $60,316
table: Gross profit $38,040 $37,918 $40,913 $46,876
table: Net income (loss) $(12,272) $(5,771) $173 $51
table: Net loss per share-basic $(0.16) $(0.08) $— $—
table: Net loss per share-diluted $(0.16) $(0.08) $— $—
table: Quarter Ended
table: March 31, June 30, September 30, December 31,
table: 2018 2018 2018 2018
table: Revenue $49,183 $60,713 $60,502 $61,825
table: Gross profit $37,299 $47,526 $47,488 $48,014
table: Net loss $(19,670) $(4,532) $(1,807) $(1,608)
table: Net loss per share-basic $(0.27) $(0.06) $(0.02) $(0.02)
table: Net loss per share-diluted $(0.27) $(0.06) $(0.02) $(0.02)
question: Analyse this data from a financial earnings document. What is the difference in revenue between December 31,2018 to December 31,2019?