Yup, this proposed index is meaningless. Sorry for my bad english, and the index name could be revised.
It aims at measuring the team how many homegrown players they had, and how many players from their own country. The more homegrown players you have, the higher index it will be. Besides nationality, the salary is also taken into account. The importance of the player is based on the % out of the team total salary.
Homegrown players: 100% ; Players from own country: 50%.
Let's use "Forty-two"
(35601) as an example:
Team total salary: $91,823 (13 players as of 17 May 2015)
Homegrown players: Gaétan Le Mell (6.4%), Pierre Caillot(6.2%), Jonathan Fouquet(4.7%), Benjamin Vedel(4.5%) and Renaud Grail(4.3%)
Players from own country: Cyril Thierry(8.2%) and Jeff Lahaye(4.1%)
*Note: (%) means the importance, Semeonas Kozurovas
(12045496) has salary of $32,953, so the importance is 32,953/91,823 = 35.9%
Homegrown Meaningless Index = 6.4% + 6.2% + 4.7% + 4.5% + 4.3% + (8.2% + 4.1%)x50% = approx. 32%
If HMI is lower than 10%, 1 ball in all categories of fan survey;
If HMI is lower than 20%, attendance of home game will not be more than 50%;
If HMI is lower than 30%, you will get less merchadising income;
30%~70%, no impact at all.
If HMI is more than 70%, it will result in better merchadising income;
If HMI is more than 80%, it will result in better attendance for home game (even if you lost previous game);
If HMI is more than 90%, you will get better fan survey;
If HMI is 100%, 5 balls in all categories of fan survey.