how to work out percentage decrease

1:29

4:16

3:36

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کوتاه

کوتاه

کوتاه

19:37

3:27

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3:54

20:11

1:49

1:50

10:03

2:54

2:03

2:00

8:24

4:24

5:46

1:36

5:56

34:05

5:34

54:33

4:22

39:21

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15:05

7:23

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8:08

6:02

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