You have text fields that have the same name. When the form is input, only the last field with that field name will be submitted. You can see this if you print out the value of $_POST
echo '<pre>'; print_r($_POST); echo '</pre>';
If you want to have multiple fields with the same name then you need to set up arrays to handle them. For example:
<input type="text" name='rows[0][ppu]' />
<input type="text" name='rows[1][ppu]' />
etc....
