There are few points:

1. Probably TIFF is 16 bit image. And JPEG is 8 bit so this decrease the amount of information two times
2. If there is some compression in TIFF it is lossless in JPEG it is lossy. So depend of the level of compression you can make much smaller file
3. Seems like you strip all the meta information when creating JPEG. In some cases this can make significant difference in size
4. And last you crop the image so this also decrease the size of image.

P.S. Based on the image name you show meta information for different images.

There are few points:

1. If there is some compression in TIFF it is lossless, in JPEG it is lossy. So depend of the level of compression you can make much smaller file
2. Seems like you strip all the meta information when creating JPEG. In some cases this can make significant difference in size
3. And last you crop the image so this also decrease the size of image.

P.S. Based on the image name you show meta information for different images.