Table 4.
Age and employment characteristics of miners recorded on the TEBA database, 1973–2012
| Characteristic | Median | Mean | Interquartile range | 1st- 99th percentile | Na |
|---|---|---|---|---|---|
| Age at entry (yrs) | 25 | 27.9 | 22–32 | 17–56 | 1,625,053 |
| No. of contracts | 4 | 6.3 | 1–9 | 1–26 | 1,625,053 |
| Length of first contract (days) | 365 | 669 | 350–429 | 8–5917 | 1,624,372 |
| Length of returning contract (days) | 365 | 448 | 357–392 | 8–3249 | 8,676,738 |
| Cumulative employment – days (yrs) | 2291 (6.3) | 3062 (8.4) | 732–4412 (2.0–12.1) | 8 - 11,674 (0.02–40.0) | 1,624,981 |
| Average cumulative service by commodity – days (yrs)b | |||||
| Gold | 2359 (6.5) | 3093 (8.4) | 755 to 4450 (2.1–12.2) | 8 - 11,787 (0.02–32.3) | 1,223,152 |
| Platinum | 1095 (3) | 1787 (4.9) | 367–2526 (1.0–6.9) | 8–9013 (0.02–24.7) | 392,806 |
| Coal | 1720 (4.7) | 2441 (6.7) | 366 to 3205 (1.0–8.8) | 1 to 10,578 (0–29.0) | 60,833 |
| Other | 374 (1.0) | 838 (2.3) | 365–911 (1.0–2.5) | 0–5989 (0.02–16.4) | 178,426 |
aVariation in totals due to exclusion of contracts with erroneous data, mainly termination date occurring before registration date. (Additional file 1 Supplementary note 1)
bAll service days included here, irrespective of whether the miner worked in one or multiple sectors