Complex increasing number of elements in XML schema

I'm trying to create a XSD schema rule that allows the following:

<Polynom>
  <Order>
    <Coefficients>
      <Coefficient>0</Coefficient>
    </Coefficients>
    <Coefficients>
      <Coefficient>1</Coefficient>
      <Coefficient>0</Coefficient>
    </Coefficients>
    <Coefficients>
      <Coefficient>3</Coefficient>
      <Coefficient>2</Coefficient>
      <Coefficient>1</Coefficient>
    </Coefficients>
  </Order>
</Polynom>

Now if it was only this it would be simple, however it should be possible to vary the amount of Coefficients. So if I add another one, that one MUST have four Coefficient

I'm not even sure this is possible with xsd?