Time (yrs),Monthly cost ($)
1988,8700
1988,8500
1988,8000
1988,7500
1988,8300
1988,9500
1988,3600
1988,6700
1988,3200
1989,7200
1989,7500
1989,9200
1989,4100
1989,5800
1989,6300
1989,6400
1989,7900
1989,4800
1990,6500
1990,6900
1990,9100
1990,3900
1990,5800
1990,6100
1990,6000
1990,5300
1990,8200
1991,4500
1991,6000
1991,5400
1991,7500
1991,8600
1991,4500
1991,5600
1991,7500
1991,8000
1992,5800
1992,5000
1992,7900
1992,3900
1992,4600
1992,5500
1992,8500
1992,6900
1992,7200
1993,5700
1993,5000
1993,5500
1993,7300
1993,4200
1993,4000
1993,6000
1993,6500
1993,4800
1994,5600
1994,5500
1994,3800
1994,11500
1994,6500
1994,7500
1994,6000
1994,4800
1994,7100
1995,5500
1995,3900
1995,5000
1995,4800
1995,5400
1995,7500
1995,6000
1995,9000
1995,7500
1996,5300
1996,2900
1996,5500
1996,5000
1996,3400
1996,6800
1996,5900
1996,6500
1996,7200
1997,4900
1997,5000
1997,6500
1997,7000
1997,5500
1997,3200
1997,3000
1997,4700
1997,4000