Cochlear implant data from 
Nunez-Anton, V. and Woodworth, G.G. (1994). Analysis of Longitudinal Data with Unequally Spaced Observations and Time-Dependent Correlated Errors.  Biometrics 50, 445-456.

Information below and quote are from this paper.  

Times are months.  Groups G are two types of cochlear implants, A or B.
"The data consist of percent correct scores on a sentence test administered under audition-only conditions to groups of subjects wearing two different cochlear implants, referred to here as A and B.  The electrode array was surgically implanted 5 to 6 weeks prior to being electrically connected to the external speech processor.  Subjects were profoundly, bilaterally deaf, thus preconnection baseline values for the sentence test were all zero.  At the time of the analysis reported here, data were available for 23 subjects in group A and 21 subjects in group B, with measurements scheduled at 1, 9, 18, 30 months after connection." 



 G  t=1   t=9  t=18  t=30
 A 28.57 53.00 57.83 59.22
 A ----- 13.00 21.00 26.50
 A 60.37 86.41 ----- -----
 A 33.87 55.50 61.06 -----
 A  1.61  0.60 ----- -----
 A 26.04 61.98 67.28 -----
 A ----- 59.00 66.80 83.20
 A 11.29 38.02 ----- -----
 A  0.00  0.00  0.00  2.76
 A ----- 35.10 37.79 54.80
 A 16.00 33.00 45.39 40.09
 A 40.55 50.69 41.70 52.07
 A  3.90 11.06  4.15 14.90
 A  1.80  2.30  2.53  2.53
 A ----- 17.74 44.70 48.85
 A 64.75 84.50 92.40 95.39
 A 38.25 81.57 89.63 -----
 A 67.50 91.47 92.86 -----
 A 45.62 58.00 ----- -----
 A  0.00  0.00 37.00 -----
 A 51.15 66.13 ----- -----
 A  0.00 48.16 ----- -----
 A  0.00  0.92 ----- -----
 B -----  0.00  0.90  1.61 
 B  0.00  0.00  0.00 -----
 B  0.00  0.00 ----- -----
 B  8.76 24.42 ----- -----
 B  0.00 20.79 27.42 31.80
 B  2.30 12.67 28.80 24.42
 B 12.90 28.34 ----- -----
 B ----- 45.50 43.32 36.80
 B 68.00 96.08 97.47 99.00
 B 20.28 41.01 51.15 61.98
 B 65.90 81.30 71.20 70.00
 B  0.00  8.76 16.59 14.75
 B  0.00  0.00  0.00  0.00
 B  9.22 14.98  9.68 -----
 B 11.29 44.47 62.90 68.20
 B 30.88 29.72 ----- -----
 B 29.72 41.40 64.00 -----
 B  0.00 43.55 48.16 -----
 B  0.00  0.00 ----- -----
 B  8.76 60.00 ----- -----
 B  8.00 25.00 30.88 55.53