I can not add ‘total’ as word under year column

I need to add total wood in overall total for each column. It does not work because “total” is character and cannot be placed in a numeric variable. Below is the code i am using:

proc sql;
 create table final as
     select year,
            count(distinct id) as total_persons,
            count(distinct case when age_cat = '20-25' then id end) as tot_20_25, 
            count(distinct case when age_cat = '25-30' then id end) as tot_25_30, 
            count(distinct case when age_cat = '30-35' then id end) as tot_30_35 
     from old_table
     group by year
     union all
     select 'Total',/*Here is line error, if i leave there just quotes works but it is not appropriate.*/
            count(distinct id) as total_persons,
            count(distinct case when age_cat = '20-25' then id end) as tot_20_25, 
            count(distinct case when age_cat = '25-30' then id end) as tot_25_30, 
            count(distinct case when age_cat = '30-35' then id end) as tot_30_35 
     from old_table;

Answer

The problem is the type inconsistency. In SQL, you would fix this by converting the year to a string:

cast(year as varchar(255))

In proc sql, you can use put:

put(year, 15.)