Possible Clues:

• 75%
• Next clue needs this for a diarist's age
• The four of them are not altogether what's on the field
• They're not, being only four, this proportion of fifteen (5-8)
• Seventy-five per cent - four of fifteen
• Not all back on the field
• More than half of fifteen
• 75 per cent
• Perhaps all inside, yet not all (5, 8)
• Not 75% of 14