how to calculate slope of a graph in origin

1:01

2:28

4:40

2:41

2:11

6:52

10:11

18:33

1:46

10:21

32:05

21:12

5:53

32:09

3:13

3:46

15:01

8:39

12:53

15:16

4:14

8:59

13:18

10:08

9:11

14:17

3:50

11:11

6:00

4:21

9:04

2:29

5:02

13:42

3:48

9:21

2:21

5:32

2:00

6:42

4:10

4:24

7:12

2:12

4:43

4:56

17:10

4:00

1:57

3:01

4:13

5:25

2:39

5:39

8:06

15:43

27:54

7:12

14:34

31:21