How can I initialize and dynamically allocate an int pointer member in an array of structs?

How can I initialize and dynamically allocate an int pointer that is in an array of structs?

My program allows me to print enroll[0].grades[x], but when I try to access any other index value of enroll other than 0 (such as enroll[1].grades[x] or enroll[2].grades[x]), my program segmentation faults.

Here's my code...

How can I make enroll[2].grades[x], for example, initialize and equal zero?

In my struct:

struct Enroll
{
        int *grades;
};

In main:

struct Enroll *enroll = (struct Enroll *) calloc(count.enroll, 10 * sizeof(struct Enroll));

enroll->grades = (int *) calloc(count.grades, 10 * sizeof(int));

In functions:

enroll[x].grades[y];