use strict;
use warnings;

my $previous_x = 0;

while (<DATA>) {
    my ($x, $y) = split;
    next if $x < $previous_x;
    $previous_x = $x;
    print;
}

__DATA__
0.0036759    0.4018006
0.0036962    0.4074616
0.0037064    0.4124646
[rest of input data omitted for brevity]

##</code><code>##

0.0036759    0.4018006
0.0036962    0.4074616
0.0037064    0.4124646
0.0037064    0.4216399
0.0037166    0.4351084
0.0037166    0.4438854
0.0037268    0.4518142
0.0037268    0.4628417
0.0037370    0.4730210
0.0037370    0.4832176
0.0037370    0.4894152
0.0037471    0.4952320
0.0037675    0.4979326
0.0037879    0.5014988
0.0038082    0.5057747
0.0038184    0.5166984
0.0038286    0.5332830
0.0038286    0.5613627
0.0038388    0.6026338
0.0038591    0.6216075
0.0038693    0.6343489
0.0038693    0.6420872
0.0038693    0.6536515
0.0038693    0.6709805
0.0038795    0.6808655
0.0038897    0.6866130
0.0039202    0.6981425
0.0039406    0.7057251
0.0039610    0.7105550
0.0039610    0.7216518
0.0039712    0.7329564
0.0039712    0.7433434
0.0039813    0.7482426
0.0039813    0.7577987
0.0039915    0.7713018
0.0040119    0.7911064
0.0040119    0.8014242
0.0040221    0.8074314
0.0040221    0.8130404
0.0040221    0.8210730
0.0040221    0.8264223
0.0040526    0.8290191
0.0040628    0.8323083
0.0040933    0.8361688
0.0041035    0.8409814
0.0041239    0.8466942
0.0041239    0.8591068
0.0041341    0.864785
0.0041443    0.8760895
0.0041544    0.8858707
0.0041646    0.8995296
0.0041748    0.9034420
0.0041748    0.9111804
0.0041748    0.9187110
0.0041850    0.9221387
0.0041850    0.9288903
0.0041850    0.9357977
0.0041952    0.9453537

##</code><code>##

next if $x <= $previous_x;