Datafile Name: Medflies
Story Names: Gompertz's Law
Reference: Carey, J. R., Liedo, P., Orozco, D., and Vaupel, J. W. (1992), "Slowing of Mortality Rates at Older Ages in Large Medfly Cohorts," Science , 258, 457-461.
Authorization: free use
Description: By using Mediterranean fruit flies, Gompertz's 1825 theory that mortality rates increase at an exponential rate as age increases is examined. (i.e. as an organism gets older, its chance of dying per unit of time increase exponentially.) 1,203,646 fruit flies comprised the population for this experiment and the number of flies found dead each day was recorded. Hence, the data consist of the number of surviving flies on each day, up until day 171 when the last two flies died.
Number of cases: 173
Variable Names:
  1. day: day number
  2. living: Number of medflies alive at the beginning of the day
  3. mort.rate: Mortality rate for the flies for each day
The Data: 
day	living	mort.rate
0	1203646	0
1	1203646	0.0014
2	1201913	0.0040
3	1197098	0.0051
4	1191020	0.0064
5	1183419	0.0075
6	1174502	0.0098
7	1163026	0.0123
8	1148693	0.0164
9	1129836	0.0218
10	1105164	0.0298
11	1072209	0.0379
12	1031620	0.0452
13	984980	0.0589
14	927011	0.0634
15	868202	0.0722
16	805489	0.0757
17	744520	0.0793
18	685514	0.0826
19	628866	0.0850
20	575420	0.0923
21	522319	0.0968
22	471756	0.1002
23	424469	0.1059
24	379537	0.1102
25	337704	0.1158
26	298596	0.1299
27	259811	0.1336
28	225101	0.1361
29	194464	0.1280
30	169569	0.1213
31	149002	0.1214
32	130911	0.1168
33	115618	0.1241
34	101271	0.1250
35	88612	0.1266
36	77390	0.1224
37	67921	0.1338
38	58830	0.1154
39	52043	0.1249
40	45544	0.1212
41	40022	0.1279
42	34902	0.1301
43	30360	0.1366
44	26214	0.1439
45	22441	0.1360
46	19390	0.1306
47	16857	0.1361
48	14562	0.1452
49	12447	0.1338
50	10782	0.1515
51	9149	0.1360
52	7905	0.1456
53	6754	0.1501
54	5740	0.1326
55	4979	0.1603
56	4181	0.1605
57	3510	0.1581
58	2955	0.1672
59	2461	0.1601
60	2067	0.1316
61	1795	0.1309
62	1560	0.1250
63	1365	0.1341
64	1182	0.1413
65	1015	0.1685
66	844	0.1220
67	741	0.1363
68	640	0.1047
69	573	0.1257
70	501	0.0798
71	461	0.1193
72	406	0.1207
73	357	0.1092
74	318	0.1038
75	285	0.0912
76	259	0.1274
77	226	0.0664
78	211	0.0806
79	194	0.0670
80	181	0.0663
81	169	0.0769
82	156	0.0897
83	142	0.0845
84	130	0.0615
85	122	0.0574
86	115	0.0522
87	109	0.1009
88	98	0.0714
89	91	0.0000
90	91	0.0549
91	86	0.0116
92	85	0.0706
93	79	0.0759
94	73	0.0274
95	71	0.0563
96	67	0.0149
97	66	0.0152
98	65	0.0462
99	62	0.0000
100	62	0.0000
101	62	0.0000
102	62	0.0645
103	58	0.0172
104	57	0.0351
105	55	0.0182
106	54	0.0185
107	53	0.0000
108	53	0.0189
109	52	0.0192
110	51	0.0392
111	49	0.0408
112	47	0.0426
113	45	0.0444
114	43	0.0233
115	42	0.0476
116	40	0.0000
117	40	0.0000
118	40	0.0000
119	40	0.0250
120	39	0.0513
121	37	0.0270
122	36	0.0833
123	33	0.0000
124	33	0.0606
125	31	0.0968
126	28	0.1071
127	25	0.0400
128	24	0.0417
129	23	0.0870
130	21	0.0000
131	21	0.0000
132	21	0.0476
133	20	0.0000
134	20	0.0000
135	20	0.0000
136	20	0.0500
137	19	0.0000
138	19	0.0000
139	19	0.0000
140	19	0.0000
141	19	0.1053
142	17	0.0588
143	16	0.1250
144	14	0.0000
145	14	0.1429
146	12	0.0833
147	11	0.0909
148	10	0.1000
149	9	0.0000
150	9	0.1111
151	8	0.0000
152	8	0.0000
153	8	0.1250
154	7	0.1429
155	6	0.1667
156	5	0.0000
157	5	0.0000
158	5	0.2000
159	4	0.0000
160	4	0.0000
161	4	0.0000
162	4	0.0000
163	4	0.0000
164	4	0.5000
165	2	0.0000
166	2	0.0000
167	2	0.0000
168	2	0.0000
169	2	0.0000
170	2	0.0000
171	2	1.0000
172	0	*