In 1999 ======> nearly 20,000
In 2007 =====> Doubles by 20, 000 to 40,000 =====> 60,000 - 40,000 ====> 20,000
Therefore, Your answer would be, Range ====> 20, 000
Mean: ======> 30000
Median: ======> 30000
Range: =====> 20000
Mode: ======> All values appeared just once.
Largest: ======> 40000
Smallest: ======> 20000
Sum: =====> 60000
Count: ======> 2
Sorted Data Set: 40000, 20000
Therefore, Your answer would be, Range ====> 20, 000
Hope that helps!!!! : )