10 
BULLETIN 1480, IT. S. DEPARTMENT OF AGKICULTURE 
acres of that crop raised in each district the last }^ear for which data 
are available. 
In such States as Iowa, Kansas, and Wisconsin, where a yearly 
enumeration of acreage is made, the district weights are usually based 
on the preceding year's acreage. In many of the States the latest 
census acreage is used. Prior to 1924, when crop prices as of. the 1st 
