Visually it's a really nice looking site. If I may offer one suggestion, it would be to use a minus sign (unicode U+2212) for the negative numbers - by default,

Visually it's a really nice looking site. If I may offer one suggestion, it would be to use a minus sign (unicode U+2212) for the negative numbers - by default, for historical pre-unicode reasons, computers tend to use a hyphen instead and it just doesn't look as good, at least to my eye!