Material Master Number range

Hi,

I have assigned a number range 100000000- 109999999 for raw material type ROH & Group( Raw material).

When i am creating the material its taking number 10000000 but the current number is changing to 100000009. I have to go & change current number to upload through LSMW.

Can anyone let me know what can be the possible reason for the current number.

Thanks

John