A local variable versus a static field across calls

public class Main {
    static int calls = 0;

    static int next() {
        int local = 0;
        local++;
        calls++;
        return local * 10 + calls;
    }

    public static void main(String[] args) {
        System.out.println(next());
        System.out.println(next());
        System.out.println(next());
    }
}