2015-09-11 Six data files were created with docket numbers blanked for Parts 1, 3, and 5, and with docket numbers containing original values for Parts 2, 4, and 6.
2013-01-14 Docket numbers are 9-filled as requested by the PI.
2011-11-11 All parts are being moved to restricted access and will be available only using the restricted access procedures.
2006-03-17 Two additional data files were added
with SAS and SPSS setup files and an updated codebook for each.
2005-11-04 ICPSR data undergo a confidentiality review and are altered when necessary to limit the risk of disclosure. ICPSR also routinely creates ready-to-go data files along with setups in the major statistical software formats as well as standard codebooks to accompany the data. In addition to these procedures, ICPSR performed the following processing steps for this data collection:
- Created variable labels and/or value labels.
- Performed recodes and/or calculated derived variables.