L/-	key source by Level only
-/T	key source by Trend only
L/T	key source by both Level and Trend
-/-	no key source for this pollutant
IE	emission of specific pollutant Included Elsewhere (i.e. in another category)
NE	emission of specific pollutant Not Estimated (yet)
NA	specific pollutant not emitted from this source or activity = Not Applicable
*	no analysis done