Range (ppm)

Total

Percent

4

8

>0 ≤ 1000

8

16

>1000 ≤ 10,000

4

8

>10,000 ≤ 20,000

11

22

>20,000 ≤ 30,000

7

14

>30,000 ≤ 40,000

5

10

>40,000 ≤ 50,000

2

4

>50,000 ≤ 60,000

2

4

>60,000 ≤ 70,000

4

8

>70,000

3

6

Total

50

100