The evening preceding Chinese New Year's Day is an occasion for Chinese families to gather for the annual reunion dinner. It is also traditional for every family to thoroughly cleanse the house, in order to sweep away any ill-fortune and to make way for good incoming luck. Windows and doors will be decorated with red color paper-cuts and couplets with popular themes of "good fortune" or "happiness", "wealth", and "longevity". Other activities include lighting firecrackers and giving money in red paper envelopes. Among about one third of the Mainland population, or 500 million Northerners, dumplings (especially those of vegetarian fillings) feature prominently in the meals celebrating the festival.