A strictly unofficial way of seeing whether you are on target for a decent life list...
Simply divide the number of different BOU species on your list by your age. My guideline below will tell you how you're doing.
Ages 12-18
Average - 8 or below
Good - Between 8+12
Excellent 12 & above
19-24
Average - 7 or below
Good - Between 7+11
Excellent 11 & above
25-30
Average - 6 or below
Good - Between 6+11
Excellent - 11 & above
31-35
Average - 6 or below
Good - Between 6+10
Excellent - 10 or above
36-40
Average - 5 or below
Good - Between 5+10
Excellent - 10 or above
41-45
Average - 5 or below
Good - Between 5+9½
Excellent - 9½ or above
45-50
Average - 4½ or below
Good - Between 4½+8½
Very Good - Between 7½ + 8½
Excellent - 8½ or above
51-55
Average - 4 or below
Good - Between 4+7
Very Good Between 7+8
Excellent - 8 or above
56-60
Average - 4 or below
Good - Between 4+6½
Very Good Between 6½+7½
Excellent - 7½ or above
61+
Average - 3½ or below
Good - Between 3½ + 6
Very Good Between 6+7
Excellent - 7 or above
my ratings still good - although I went off birding for about fifteen years - and I'm only thirty!!!!
superly doopely
Mine is just over 10¼ and I'm 31. Using age fractions (eg I'm actually 31.67 years old) It reached 10 for the first time in July with a Cattle Egret in Cambridgeshire !!!