validate industry NAICS codes
Examples
EJAM:::naics_is.valid(c(22, "022", " 22", 111, "4239", 423860))
# table(EJAM:::naics_is.valid(frs_by_naics$NAICS)) / NROW(frs_by_naics)
validate industry NAICS codes
EJAM:::naics_is.valid(c(22, "022", " 22", 111, "4239", 423860))
# table(EJAM:::naics_is.valid(frs_by_naics$NAICS)) / NROW(frs_by_naics)