Dear Vijay,
Don't have time to work on the above bucket since it need more effort.
Below the buckets with few modifications and i hope even the below is good to go for you.
Also, i believe that captured numbers are in Milliseconds. If not, logic will also change.
More than 50 Sec : \d
Less than 10 Sec : ^([0-9]|[0-9][0-9]|[0-9][0-9][0-9]|[0-9][0-9][0-9][0-9])$
10 to 19 Sec : ^([1][0-9][0-9][0-9][0-9])$
20 to 29 Sec : ^([2][0-9][0-9][0-9][0-9])$
30 to 39 Sec : ^([3][0-9][0-9][0-9][0-9])$
40 to 49 Sec : : ^([4][0-9][0-9][0-9][0-9])$
The rules must be placed in the same order.
Thank You!
Arun