C:\chas_sandbox>type test653837.txt
3
5 6 7
2 22 222
10 9

C:\chas_sandbox>perl -lane "$seed = 1.04 unless $seed;$diff=$F[0]-$seed;if ($dif
f>=0.1) {print join(' ',@F);$seed=$F[0];}" test653837.txt
3
5 6 7
10 9