I keep getting a "missing return statement" error on my Java and I can't figure out why. Any thoughts on what I'm doing wrong? Errors start with the setYearModel mutator and continue through the end of the program.

public class Car_V2

{

private String carName;

private int yearModel;

private String carMake;

private int carSpeed;

private int carMileage;

private Owner carOwner;

private static int totalMileage;

public Car_V2(String name, int year, String make, int speed, Owner owner, int mileage)

{

carName = name;

yearModel = year;

carMake = make;

carSpeed = speed;

carOwner = owner;

carMileage = mileage;

totalMileage += mileage;

}

public String toString()

{

String response = "";

response += "Car Name is: " + carName;

response += " Car Year is: " + yearModel;

response += " Car Make is: " + carMake;

response += " Car Speed is: " + carMake;

response += " It was " + carOwner.toString();

return response;

}

public String getCarName()

{

return carName;

}

public int getYearModel()

{

return yearModel;

}

public String getMake()

{

return carMake;

}

public int getSpeed()

{

return carSpeed;

}

public String getOwner()

{

return carOwner.toString();

}

public int getMileage()

{

return carMileage;

}

public static double getTotMileage()

{

return totalMileage;

}

public void setCarName(String na)

{

carName = na;

}

public int setYearModel(int y)

{

yearModel = y;

}

public String setMake(String ma)

{

carMake = ma;

}

public int setSpeed(int s)

{

carSpeed = s;

}

public String setOwner(String o)

{

carOwner.toString();

}

public int setMileage(int mi)

{

carMileage = mi;

}

}