hook_webform_submission_presave store select option not key

I am working with webforms and have a long Select option list which gets regularly refreshed and I need to store the submission option value to preserve the data for reporting.

On Drupal 7 the key value field is stored in the data field next the the cid is there a way to change this to the Option Value.

I created a new database field and created a function for hook_webform_submission_presave to pick up the submitted value data value and pass the value into the new field component, but the data passed is the Key Value so it doesn't work, is there a way I can hook into the Option value to pass it into a new field to store it?

function PS9_SSA_webform_submission_presave($node, &$submission) {
$submission->data[78][0] = $submission->data[18][0];
}

or am I tackling this the wrong way is there another way to achieve storing the Option not just the Key value?