Only 4, 4 Times

My Table

0 = $(4-4)+(4-4)$

1 = $\frac{4}{4} + (4-4)$

2 = $\frac{4}{4} + \frac{4}{4}$

3 = $4-(4^{4-4})$

4 = $4+((4-4).4)$

5 = $4+(4^{4-4})$

6 = $(4-4)+(4+\sqrt{4})$

7 = $\frac{4}{4}+(4+\sqrt{4})$

8 = $(4+4)+(4-4)$

9 = $?$

10 = $(4+4x4)-\sqrt{4}$

11 = $?$

12 = $?$

13 = $?$

14 = $4+4+4+\sqrt{4}$

15 = $?$

16 = $4+4+4+4$

17 = $?$

18 = $4!-(4+4-\sqrt{4})$

19 = $4!-(4+\frac{4}{4})$

20 = $?$