It’s an estimate of the number of people who died, there are several reports that give different estimates. However, the number is certainly high. In 1921 the Tusla Tribune initially gave a figure of 9 white deaths and 36 black deaths, they later revised the figure to 176 deaths.
The indiscriminate killing of people was followed by arson, as a result some bodies must have been burnt in the fire. Even if you were present a day after the killings, determining the exact number of death would have been an impossible task using 1921 technology. You cannot get an exact number.
Other factors may also hinder the authorities from getting an exact number, for example in recent genocides and massacres some people hurriedly bury their loved ones in shallow graves before escaping to safety and dogs and wild animals ate the dead bodies before they were found, counted and burried.
Many innocent people died, that’s what matters.