Unstable to testing delay

insert into movement select t.pid,t.testing,t.unstable from (select distinct
    l1.package_id as pid, min(l1.day) as testing, min(l2.day) as unstable from lifetimes as l1 left join lifetimes as l2 on
    l1.package_id=l2.package_id and l1.archive_id = 11 and l2.archive_id = 4 where l1.archive_id is not null and
    l2.archive_id is not null group by l1.package_id) as t;
create table delay (name varchar(64), version varchar(64), delay int);
insert into delay select u.name,v.version,datediff(m.unstable,m.testing) as delay from movement as m, units as u, packages as p, versions as v where p.id = m.package_id and v.id = p.version_id and u.id = p.unit_id order by delay desc;
select min(delay),avg(delay),max(delay) from delay;