Use placeholders for get statistics information.
Examples:
My kills in overworld: %sms_kills_world%
My kills in nether: %sms_kills_nether%
My kills in other world: %sms_kills_<world name>%
This plugin support Multiverse Core just enter your custom world name in <world_name>

Now you can use next placeholders:
%sms_kills_world% — number of player kills
%sms_deaths_world% — number of deaths
%sms_killentity_world% — number of mob kills
%sms_blockplace_world% — number of blocks placed
%sms_blockbroken_world% — number of blocks broken
%sms_playtime_world% — time in HH:MM:SS format
%sms_rawplaytime_world% — raw time in seconds
%sms_damagedeal_world% — damage dealt
%sms_damagetake_world% — damage taken

In config.yml you can enable / disable placeholders or plugin