Solution

164128

First name
Jasper
School
Highgate
Country
Age
0

So i first thought to go up in 1s and 2s so how many 1s there was then 2s then 3s all the way up to 10. I found out that 1 was just 10 and i just flipped each time so it would be the opposite. So if i was trying to find 1000 I i would just do 1000 + 999 + 998 etc.