percentile in sgplot

[capam]

Hi,

I'm using SE guide 9.4. I'd like to modify the code below to replace the refline inputs with computed values of 10th percentile and 90th percentile. 

How do I manipulate count and then use the percentile variables in the sgplot below? Or, is there a better way?

Thanks.

proc sgplot data=loco_20_0001_freq;
	scatter x=unit y=count / datalabel=unit;
	refline 22.7  / label="10%" LINEATTRS=(color=red);
	refline  31 / label="90%" LINEATTRS=(color=red);
	xaxis display=(nolabel noline noticks) 
		fitpolicy=rotate 
		valuesrotate=vertical;
	yaxis grid;
	title 'Incident Occurrences';
run;

[ballardw]

The basic approach would be to use another procedure such as proc means to generate the desired percentile of a variable similar to:

proc means data=sashelp.class p10 p20;
  var height;
run;

Look at the output and replace the values in the refline statements.

If you want to automate then you get into macro coding to generate output from proc means, create macro variables and then reference the macro variables in the sgplot code.