Question: How many papers were published in 2005. Calculate the difference between the number of paper published in 2005 and the number of paper published in the previous year.
SQL: SELECT SUM(CASE WHEN Year = 2005 THEN 1 ELSE 0 END) , SUM(CASE WHEN year = 2005 THEN 1 ELSE 0 END) - SUM(CASE WHEN year = 2004 THEN 1 ELSE 0 END) AS diff FROM Paper