Issue with natural sorting

[mmadia]

hrev45285

#!/bin/bash
files="001-.txt \
	001.txt \
	01-.txt \
	01.txt \
	1-.txt \
	1-0-.txt \
	1-0.txt \
	1.txt"
	
for file in $files; do 
	touch $file
done

~/Desktop/test> ls -1
001-.txt
001.txt
01-.txt
01.txt
1-.txt
1-0-.txt
1-0.txt
1.txt
test-files.sh