How to decrease a Slider value by time?

Hi! I have a slider that updates 10 by 10 from 0 to 100 when an Enemy is dead. When it arrives to 100, I want to decrease my slider in 10 seconds. I know, maybe it’s a newbie question, but I didn’t find an answer in anywhere.

Here is my EnemyHealth code that increases the slider:

public Slider shootSlider;
public int powerCharge = 10;
void Death ()
{
isDead = true;

    capsuleCollider.isTrigger = true;

    anim.SetTrigger ("Dead");

    enemyAudio.clip = deathClip;
    enemyAudio.Play ();

    //Here my slider is increased when an enemy dies
shootSlider.value += powerCharge;
}

Can somebody help me, please?

Tested and works

public Slider enemySlider;

public void DecreseEnemySlider()
{
    StartCoroutine(DecreseSlider(enemySlider));
}

IEnumerator DecreseSlider(Slider slider)
{
    if (slider != null)
    {
        float timeSlice = (slider.value / 10);
        while (slider.value >= 0)
        {
            slider.value -= timeSlice;
            yield return new WaitForSeconds(1);
            if (slider.value <= 0)
                break;
        }
    }
    yield return null;
}