The film that you have is most likely one of the four Motion Picture Black & White Films manufactured using a punch hole every fourth perforation on one perforation track. From the color of the stock (solarized), it would appear that you have either 5302, a Black & White print film, or 2360, a low contrast B&W print film. Kodak added these additional holes as frame line markers in February, 2004 when they eliminated the equipment that produced ink application frame-line markers.