Bootstrap 3 - Nested Rows

HTML

<link rel="stylesheet" href="http://getbootstrap.com/dist/css/bootstrap.css">
<script src="http://getbootstrap.com/dist/js/bootstrap.js"></script>
<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/font-awesome/4.1.0/css/font-awesome.min.css">
<div class="container">
        <div class="row">
            <div class="col-xs-6">
                <div class="big-box">image</div>
            </div>
            <div class="col-xs-6">
                <div class="row">
                    <div class="col-xs-4"><div class="mini-box">1</div></div>
                    <div class="col-xs-4"><div class="mini-box">2</div></div>
                    <div class="col-xs-4"><div class="mini-box">3</div></div>
                    
                </div>
                <div class="row">
                    <div class="col-xs-4"><div class="mini-box">1</div></div>
                    <div class="col-xs-4"><div class="mini-box">2</div></div>
                    <div class="col-xs-4"><div class="mini-box">3</div></div>
                    
                </div>
            </div>
        </div>
        <div class="row">
            <div class="col-xs-2"><div class="mini-box">1</div></div>
            <div class="col-xs-2"><div class="mini-box">2</div></div>
            <div class="col-xs-2"><div class="mini-box">3</div></div>
            <div class="col-xs-2"><div class="mini-box">4</div></div>
            <div class="col-xs-2"><div class="mini-box">5</div></div>
            <div class="col-xs-2"><div class="mini-box">6</div></div>
            
            </div>
        <div class="row">
            <div class="col-xs-2"><div class="mini-box">1</div></div>
            <div class="col-xs-2"><div class="mini-box">2</div></div>
            <div class="col-xs-2"><div class="mini-box">3</div></div>
            <div class="col-xs-2"><div class="mini-box">4</div></div>
            <div class="col-xs-2"><div class="mini-box">5</div></div>
            <div class="col-xs-2"><div...

CSS

.big-box,
.mini-box {
    background-color: #10BCFF;
    color: white;
    text-align: center;
    margin: 2px;
    font-size: 1.5em;
}
.big-box {
    height: 65px
}
.mini-box {
    height: 30px
}