protected void endStatistics(String html) {
		//calculate compression time
		if(generateStatistics) {
			statistics.setTime((new Date()).getTime() - statistics.getTime());
			statistics.getCompressedMetrics().setFilesize(html.length());
			
			//calculate number of empty chars
			Matcher matcher = emptyPattern.matcher(html);
			while(matcher.find()) {
				statistics.getCompressedMetrics().setEmptyChars(statistics.getCompressedMetrics().getEmptyChars() + 1);
			}
		}
	}