an $N$-layer graphene can be estimated by combining $\sigma^N_{j=1,\cdots,N}$ with the transfer matrix method.

In this paper, we define the former $\sigma_N$ as a bunched conductivity and the latter $\sigma^N_{j=1,\cdots,N}$ as a layered conductivity. We quantified the differences between the two conductivities for the AB and AA stacking orders in the collisionless limit. By comparing the calculated results from the two formulations for a sufficiently large $N$ value with reflectance measurements of graphite in a quantitative manner, we point out a small deviation between theory and experiment. The layered conductivity underestimates the reflectance of graphite at low photon energies. It is explained by the effect of a nonlocal conductivity on the reflectance. We then propose to investigate the absorptance as a function of $N$. In a previous paper, we calculated the optical properties of an $N$-layer graphene and found that a characteristic peak structure appears in the absorption spectrum, regardless of the photon energy, at the layer number $N=2/\pi \alpha \simeq 87$, where $\alpha$ is the fine-structure constant. [@Sasaki2020a] This is a universal layer number found by assuming that any correlation between layers is negligible besides electromagnetic fields. We will show that a correction by interlayer electronic interaction to the 