Grouping Tags And Surrounding Each Group With DIV

Code:
<script src="[URL]" type="text/javascript"></script>
<script>
$(document).ready(function(){
var playlistContentBuilderSearch='';
var contentLength = 7;

for(var i=0;i < contentLength;i++){
playlistContentBuilderSearch += "<li class='searchResultsItem'>";
playlistContentBuilderSearch += "<h4>Title</h4>";
playlistContentBuilderSearch += "<p>lalala</p>";
playlistContentBuilderSearch += "</li>";
} .....

As you may have guessed contentLength is dynamic, coming from webservice. For this example its value is 7 but it can be 9 or 23 etc.. The idea is to group the <li> tags in six surrounded by numbered divs for each group, just like the previous example. How can I do it?