Dart 2dr Post prioduction

I can't find any info that tells me how many of the 1968 Dart 2dr Post cars were built. Does anyone have any info that might be helpful? Was there a specific designation to the 2dr Post? I was just curious how many of my car are out there.

1968 Dodge Dart 2dr Post
/6-auto
small rear
drum brakes
Probably a bench seat....

Thanks

j