A drive to excellence always seeks improvement. If you accept 95% efficiency as a vision or goal, the efficiency will inevitably slip to 90%. If that’s considered “good enough,” it will become hard to keep it above 85% and so on and so on.
A vision is a goal that is strived to be achieved.
Goals must not be unrealistic or unattainable, or your followers will simply give up trying altogether, becoming dispirited and demoralized in the process. If 95% of people fail to meet a standard, then that standard is likely too high and must be reviewed and changed.
The same goes if the bar is set so low where little or no effort is required to meet it. Based on your vision, set high goals that are attainable but with some degree of difficulty, and reward those who meet the goals. If a large number of followers are meeting the goal, raise the target a little.
If only a very few are meeting it, lower it somewhat, or ask yourself why? Investigate any potential bottlenecks that may be holding back progress and resolve them. Talk to your followers about possible solutions. The people who actually do the work are sometimes far more likely to be able to tell you why they are having difficulty accomplishing a task or goal than even their immediate supervisors or managers.