Not playing whole animation

Facing weird problem with splitting animation, everything fine but when I call "idle" animation it doesn't play all frames.

public class animControl: MonoBehaviour {

 private Animation mainAnimation;
 //public AnimationClip idle;
 // Use this for initialization
 void Start () {
     
     mainAnimation= GetComponent<Animation>();
     
     mainAnimation.clip.legacy = true;

     mainAnimation.AddClip(mainAnimation.clip, "_idle", 0,99);
     mainAnimation.wrapMode = WrapMode.Loop;
     mainAnimation["_idle"].layer = -1;
     mainAnimation.Stop();

     mainAnimation.Play("_idle");
 }

}

I tried to change all frames number but still it doesn't play more than 30 frames.