As the diverging lines on the graph show, Hong Kong faces very different futures. But at present government departments cannot even agree a common estimate among themselves. Every five years the Government produces a 20-year projection of population. (The most recent was issued in 1997 and is shown on the graph in blue.) Unfortunately, these estimates have been so frequently wrong that the planning and transport departments, who are most in need of long-term projections, have started to come up with their own estimates. Ava Ng Tse Suk-ying, deputy director of planning, explains that the two departments use three estimates of their own, one of which is basically the same as that used by the rest of the Government and the other two are higher by varying amounts (shown in red). These figures are higher than those used by the rest of government because 'It's easier to postpone a project than to bring it forward', she says. If the Government were to implement the ruling on permanent residency delivered by the Court of Final Appeal, which would mean any permanent resident could come to live in Hong Kong without undue delay, the Government's estimate of future population would be the line shown in green. While Secretary for Security Regina Ip Lau Suk-yee told Legco that allowing the mainland children to come to Hong Kong would pose 'a heavy and even unbearable burden to Hong Kong', the graph shows that both Planning and Transport departments are already planning for higher figures than this.