Table:
text: Hydrological code
United States
United States
Name_ Level_ Digits Average_size_square_miles Number_of_HUs_approximate Example_name Example_code_HUC
Region 1 2 177560 21 Pacific Northwest 17
Subregion 2 4 16800 222 Lower Snake 1706
Basin 3 6 10596 370 Lower Snake 170601
Subbasin 4 8 700 2200 Imnaha River 17060102
Watershed 5 10 227 (40,000–250,000 acres) 22000 Upper Imnaha River 1706010201
Subwatershed 6 12 40 (10,000–40,000 acres) 160000 South Fork Imnaha River 170601020101

Question: What is the hydrological code of the middle Huc example code if the bottom snake of the example name has 6 digits and less than 3 levels?

Question: What is the approximate number of HUs in the hydrological code if there are more than 2 digits and 6 levels?

Question: How many HUC example codes among hydrological codes have 1 level?

Question: Considering the hydrological code, what is the mean level number if the sample name is Lower Snake and the approximate number Hus is less than 370?