[xsl] looping on a line

How would you go about looping on a line e.g. going
from this...

<data>389,456,789</data>
<data>912</data>
<data>917,421</data>
<data>389,456,789,561,123,754</data>

to this...

<no>389</no>
<no>456</no>
<no>789</no>
<no>912</no>
<no>917</no>
<no>421</no>
<no>389</no>
<no>456</no>
<no>789</no>
<no>561</no>
<no>123</no>
<no>754</no>