.classification { 
	position: relative;
	width: 91px;
	height: 17px;
    display: inline-block
}
.classification .cover {
	position: absolute;
	background: transparent url(stars.png) top left no-repeat;
	top: 0px;
	left: 0px;
	width: 91px;
	height: 17px;
	z-index: 101;
}
.classification .progress {
	position: absolute;
	background: transparent url(stars_full.png) top left no-repeat;
	top: 0px;
	left: 0px;
	height: 17px;
	z-index: 102;
}

#<div class="classification"><div class="cover"></div><div class="progress" style="width: 27%;"></div></div>