Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE department ( Department_ID int, Name text, Creation text, Ranking int, Budget_in_Billions real, Num_Employees real )
TABLE: CREATE TABLE management ( department_ID int, head_ID int, temporary_acting text )
TABLE: CREATE TABLE head ( head_ID int, name text, born_state text, age real )

### Question ###
Show average of budget in different year and group by department creation time with a line chart, and order by the X-axis in descending.

### Accurate SQL ###

SELECT Creation, AVG(Budget_in_Billions) FROM department GROUP BY Creation ORDER BY Creation DESC