create table t1 (c1 int,c2 int,c3 int); 

insert into t1 values (1,3,1),(2,1,1),(3,0,1),(4,0,1),(5,0,1),(6,0,1);

MariaDB [test]> SELECT count(*) cnt,

    ->        count(*)/((SELECT count(*) FROM t1 b WHERE b.c3 = a.c3)/100) "%"

    -> FROM t1 a WHERE c1 < 5 GROUP BY c3;

+-----+---------+

| cnt | %       |

+-----+---------+

|   4 | 66.6667 |

+-----+---------+

1 row in set (0.01 sec)

MariaDB [test]> create view v1 as 

    -> SELECT count(*) cnt,

    ->        count(*)/((SELECT count(*) FROM t1 b WHERE b.c3 = a.c3)/100) "%"

    -> FROM t1 a WHERE c1 < 5 GROUP BY c3;

Query OK, 0 rows affected (0.01 sec)

MariaDB [test]> select * from v1 ;

+-----+------------+

| cnt | %          |

+-----+------------+

|   4 | 0.00666700 |

+-----+------------+

1 row in set (0.00 sec)

MariaDB [test]> show create view v1;

+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+

| View | Create View                                                                                                                                                                                                                                           | character_set_client | collation_connection |

+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+

| v1   | CREATE ALGORITHM=UNDEFINED DEFINER=`root`@`localhost` SQL SECURITY DEFINER VIEW `v1` AS select count(0) AS `cnt`,count(0) / (select count(0) from `t1` `b` where `b`.`c3` = `a`.`c3`) / 100 AS `%` from `t1` `a` where `a`.`c1` < 5 group by `a`.`c3` | utf8                 | utf8_general_ci      |

+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+----------------------+----------------------+

1 row in set (0.00 sec)