The charges on a droplet can be used to represent the number of electrons carried by this droplet.
In other words:
a droplet having a charge of 1.60 x 10^-19 has 1.60 x 10^-19 electrons while a droplet having a charge of 3.15 x 10^-19 has 3.15 x 10^-19 electrons.
From the observations:
The fact that the droplets carried different charges signifies the fact the different droplets carried different numbers of electrons
