Household data are collected as of March. As stated in the Census's Source and Accuracy of Estimates for Income, Poverty, and Health Insurance Coverage in the United States: 2011 (http://www.census.gov/hhes/www/p60_243sa.pdf) Estimation of Median Incomes. The Census Bureau has changed the methodology for computing median income over time.
Coding CAD. The ICD-9-CM diagnosis codes for CAD are classified to subcategory 414.0x. Coding CAD requires documentation of the coronary artery involved and whether or not it is of a native artery, an artery of a transplanted heart, or a bypass graft. The fifth-digit subclassification identifies the coronary artery involved.
There may be more than one ICD 9 code associated with each CPT code. The CMS 1500 form can accommodate up to 4 ICD 9 codes in box 21 of the form as referenced by the diagnosis pointer in box 24E. Here's some links to free references for CPT medical coding and ICD 9 codes from reputable sites.