what were the top four most frequent diagnoses given to patients during the same month after being diagnosed with trachea & bronch dis nec until 1 year ago?
select d_icd_diagnoses.short_title from d_icd_diagnoses where d_icd_diagnoses.icd9_code in ( select t3.icd9_code from ( select t2.icd9_code, dense_rank() over ( order by count(*) desc ) as c1 from ( select admissions.subject_id, diagnoses_icd.charttime from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where diagnoses_icd.icd9_code = ( select d_icd_diagnoses.icd9_code from d_icd_diagnoses where d_icd_diagnoses.short_title = 'trachea & bronch dis nec' ) and datetime(diagnoses_icd.charttime) <= datetime(current_time,'-1 year') ) as t1 join ( select admissions.subject_id, diagnoses_icd.icd9_code, diagnoses_icd.charttime from diagnoses_icd join admissions on diagnoses_icd.hadm_id = admissions.hadm_id where datetime(diagnoses_icd.charttime) <= datetime(current_time,'-1 year') ) as t2 on t1.subject_id = t2.subject_id where t1.charttime < t2.charttime and datetime(t1.charttime,'start of month') = datetime(t2.charttime,'start of month') group by t2.icd9_code ) as t3 where t3.c1 <= 4 )