The number of sets by the way, is clearly infinite
Set 1. 77 repeated 13 times
Set 2 77 repeated 12 times followed by 77.1
Set 3 77 Repeated 12 times followed by 77.11
Set 4 77 Repeated 12 times followed by 77.111
Well I demonstrate it obviously with my example, but I think I can do a real proof here:
Any Set of 13 numbers containing {77,77,77,77,77,77,77,77,77,77,77,77,77} Has a sum greater than 1000 but less than 1452. ====> 77 * 12+ 77 = 1001
Any Set of 13 numbers containing {77,77,77,77,77,77,77,77,77,77,77,77,78} in any order has a sum greater than 1000 but less than 1452======> 77*12+78=1002
Their are infinate numbers X, where 77<=x<=78
Therefore there are infinite lists containting {77,77,77,77,77,77,77,77,77,77,77,77,X} where 1001<=77*12+X<=1002
Therefore there are infinite lists of 13 numbers where the sum of the numbers greater than 1000 and less than 1425
QED
Now maybe you meant whole real numbers, but I would just say any measurment you make would likely not consist of such numbers.