select name
       count(case when value <= 5 then 1 end) as "0-5",
       count(case when value > 5 and value <= 10 then 1 end) as "5-10",
       count(case when value > 10 and value <= 15 then 1 end) as "10-15"
from the_table
group by name;

With the upcoming version 9.4…