There are millions every year.
In the United States, around 70-80% of all homicides involve firearms. Additionally, guns are used in a significant number of robberies and assaults each year.
15 TO 25 Year Olds
100-250 die each year
err
It varies a little year to year, but in the U.S. according to the FBI, about 20-30 percent of all violent crime involves a gun.
Check the FBI Uniform Crime Report
There is limited data available on the number of individuals with Concealed Carry Weapon (CCW) permits who commit gun crimes each year. However, studies suggest that the rate of gun crimes committed by CCW permit holders is generally low compared to the general population of gun owners.
The answer to your question will depend on what ages you define "Kids" as.
What are you trying to ask?
In the United States, there are approximately 30,000 gun-related deaths each year. This number includes homicides, suicides, and accidental deaths.
FBI Uniform Crime Status Report and the CDC are places to start