How to calculate mean across two variables in SAS?

Question

I have a data set which contains data on the average price of unleaded regular gasoline (per gallon), whole large eggs (per dozen), and whole milk (per gallon). The variables in this file are year, month, price, and type of commodity.

Year Month  Price   Commodity
2004    1   1.592   Gas
2004    2   1.672   Gas
2005    1   1.766   Gas
2005    2   1.833   Gas
2006    1   2.009   Gas
2006    2   2.041   Gas
2004    1   1.95    Egg
2004    2   1.979   Egg
2005    1   1.97    Egg
2005    2   1.951   Egg
2006    1   2.032   Egg
2006    2   2.21    Egg
2004    1   2.879   Milk
2004    2   2.814   Milk
2005    1   2.786   Milk
2005    2   2.906   Milk
2006    1   3.374   Milk
2006    2   3.574   Milk

Can anyone help me to create a data set that contains the average price per year for each commodity?

I am able to create a data set that contains the average price per year or per commodity, but unable to calculate average price per year for each commodity.

Note: I am using SAS 9.4 version

Answer 1

From your description, this is a simple code that does what you requested:

 proc sql; select mean(price) as average, year, commodity from have group by commodity, year order by commodity, year; quit; 

This gives the output:

  average year commodity 1.9645 2004 Egg 1.9605 2005 Egg 2.121 2006 Egg 1.632 2004 Gas 1.7995 2005 Gas 2.025 2006 Gas 2.8465 2004 Milk 2.846 2005 Milk 3.474 2006 Milk