I believe these are really high share values, plus, as you introduce more referrals, your percentages increase in value too, see the chart.
Bronze
– 0-50 Active Referrals - 20% First Level, 10% Second Level
Silver – 50-150 Active Referrals - 25% First Level, 10% Second Level
Gold – 150-300 Active Referrals - 25% First Level, 15% Second Level
Platinum – 300-500 Active Referrals - 30% First Level, 15% Second Level
Elite – 500+ Active Referrals - 30% First Level, 20% Second Level