As I test on many different systems ranging from 240 MHz to 4.2 GHz, using a count isn't quite useful, so I generally op for the negative value in perl5 which makes it CPU seconds
my %results = timethese(-1.5, { ... });
Type check failed in binding $count; expected 'Int' but got 'Rat'
in sub timethese at lib/Benchmark.pm6:21