How To return null value if no records present in select query
Add 72 records with all fields NULL, get first 72 records (you sort in DESC, so NULLs will be last).

( SELECT ..... 
  ........
  order by date DESC limit 72 ) 
UNION ALL 
( SELECT x.*
  FROM ( SELECT null, null, ... null ) x,
       ( SELECT 1 UNION SELECT 2 ... UNION SELECT 72 ) y
)
order by date DESC 
/* , COALESCE('all another resultset fields list') IS NULL */ 
limit 72


COALESCE needed if date field can be NULL.

PS. Pseudotable with numbers from 1 to 72 can be generated using 2-3-4 small tables. Or in recursive CTE if DBMS allows...

PPS. In recursive CTE you can generate the required number of records up to 72 total records at once.