In this release of Quarterly Provisional Estimates,NCHS presents infant mortality rates based on final data for 2014 and provisional data for 2015. Estimates for 2015 are based on all infant death records received and processed by NCHS as of September 11, 2016. Data reported in this release represent 100% of the records included in the final (complete) 2015 data file; however, and these data absorb not undergone the standard processing,evaluation, imputations, or recoding done in the course of producing a final data file for release. As such,the term "provisional" is used throughout this report to indicate that these data may differ from the final 2015 mortality data file. Denominators for infant mortality rates (counts of live births) are based on final birth data for 2014 and 2015 (4,5).
Source: cdc.gov