st: Combine stacked and unstacked bars

[Nikolaos Kanellopoulos <nkkanel@yahoo.gr>]

Dear all,
 
I searched the Statalist archives and the web and could not find an answer to my question. 
I am sorry if this question has been posted before and skipped my attention. 
 
I have three variables over a period of ten years and I want to create a graph bar with two of them stacked over each other and the third next to them.
 
For instance in the following simple example:
 
webuse union, clear
keep idcode year age
reshape wide age, i( idcode) j( year)
keep in 1/10
graph bar  age71 age77 age88, over(idcode)
 
I want two bars. The first will be age71 age77 stacked together and the second age88.
 
Thank you in advance
Nikos 

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