New Zealand just had a general election. Their Green Party polled 6.43% of the vote, winning them 8 seats in parliament - 6.56% of the 122 seats.
In the UK general election in 2005, the Green Party of England and Wales polled 1% of the vote and won none of the 646 parliamentary seats. Proportional allocation of seats to the GP vote would be 6 seats. Not zero.
Like the Electoral Reform Society, punkscience advocates the Single Transferable Vote. We also advocate Direct Democracy and Compulsory Voting. Citizens have responsibilities as well as rights (although I'm a cosmopolitan [Article 15] and I'm opposed to the freedom to wantonly reproduce [Article 16:1]).