Add birthweight analysis-convert into grams and add to survey object
Create toddler age variable to break down <2 year old by 6 month age intervals
Explore toddler age and overall age categories
Attach toddler age to dataframe
Start making new variable for age at autsim diagnosis in months
Start examining age of autism or Developmental delay Diagnosis
Start clearning age variables. There are 37 unknown  values.
ignore figure directory in src that is generated by Markdown knitr
Comment out code that display munge results or explore the data in munge file