The area of the cable in question (.375) has a cross sectional area of .110. It may be treated as a single conductor when determining conductor fill requirements.
Chapter 9 note (5) for conductors not included in Chapter 9, such as multiconductor cables, the actual dimensions shall be used.
Chapter 9 note (9) A multi-conductor cable of two or more conductors shall be treated as a single conductor for calculating percentage conduit fill area. For cables that have elliptical cross sections, the cross-sectional area calculation shall be based on using the major diameter of the elipse as a circle diameter.