/*计算各公司高管任现职务的平均年龄，存放于dup_mean*/
/*方法一*/
proc sql;create table dup_mean as
select *,
mean(case substr(id_zhiwu,3,2) when'30' and index(zhiwu,"副") when 0 then age else . end) as age_sm_ceo
from c1
where stkcd ne .
group by stkcd,year;
quit;


/*方法二*/
proc sql;create table dup_mean as
select *,
mean(case substr(id_zhiwu,3,2) when'30' and index(zhiwu,"副")<0 then age else . end) as age_sm_ceo
from c1
where stkcd ne .
group by stkcd,year;
quit;