Hello Mam Hafsa;
for finding future growth rate in leap there is a option of Growth rate in leap follow below steps in Analysis Mode:
1. Ctrl+f = open function wizard
2. In Function Type box select "All"
3. In function you type Growth rate
4.In parameter you select data of eg. GDP, Population
if you want more help about LEAP contact me on my whats-app or email.
+92-343-3662304
engrzulfiqaralikhoso@gmail.com