Horoscope - one or two?

Birthchart has to be one and the same same throughout a person's life if only he is living in the same place where he was born. Why? Houses are the 360° circle drawn around the earth whereas the signs are 360° circle drawn up above and around the earth.  Ascendant(Lagna) is a Particular place on earth at a particular time on a particular date. A particular place or a person standing there comes to the same place against the same sky roughly after 24 hours.  We create Lagna because the planets offering results will be different to different places on earth in any given time, and different for a single place in different points of time.  When astrology was born 5000 years ago, there was no transport facility.  Almost 99% of the people lived in the same place where they were born. If a person is born in India moves to America and starts living there, in a particular longitude, he will face the events belonging to a person born in that place in his date of birth and time.  If his shifting is at the age of 20, then he should have two birth charts, one for India and another for America, in the second one prepared with same date of birth and time but with living place, first twenty years should be neglected just as in his first birth chart, "after 20 years" are to be neglected. If the birthplace and livingplace are different even if inside India, this method can be put in test.