  We characterize the intrinsic properties of any FRB using its redshift $z$,
spectral index $\alpha$ and energy $E_{33}$ in units of $10^{33} \, {\rm J}$
emitted across $2128 - 2848\; {\rm MHz}$ in the FRB's rest frame. Provided that
$z$ is inferred from the measured extra-galactic dispersion measure $DM_{\rm
Ex}$, the fluence $F$ of the observed event defines a track in $(\alpha,
E_{33})$ space which we refer to as the "energy track". Here we consider the
energy tracks for a sample of $254$ non-repeating low dispersion measure FRBs
from the CHIME/FRB Catalog-1, and use these to determine $n(E_{33} \mid
\alpha)$ the conditional energy distribution i.e. the number of FRBs in the
interval $\Delta E_{33}$ given a value of $\alpha$. Considering $-10 \le \alpha
\le 10$, we find that the entire energy scale shifts to higher energy values as
$\alpha$ is increased. For all values of $\alpha$, we can identify two distinct
energy ranges indicating that there are possibly two distinct FRB populations.
At high energies, the distribution is well fitted by a modified Schechter
function whose slope and characteristic energy both increase with $\alpha$. At
low energies, the number of FRBs are in excess of the predictions of the
modified Schechter function indicating that we may have a distinctly different
population of low-energy FRBs. We have checked that our main findings are
reasonably robust to the assumptions regarding the Galactic Halo and Host
galaxy contributions to the dispersion measure.

High Energy Astrophysical Phenomena;Cosmology and Nongalactic Astrophysics