However , these still contained many limitations and revised versions , as new information became available .
In 1977 , new growth charts were developed by the National Center for Health Statistics ( NCHS ) based on data collected by the National Health Examination Surveys .
These still contained many limitations and revised versions , as new information became available .
In 1977 , new growth charts were developed by the National Center for Health Statistics ( NCHS ) based on data collected by the National Health Examination Surveys .